1

Cerebellum

Kiranmayi S

3

Cerebellum

50 of brainrsquos neurons 10 of volumeCan change movements as necessary

ndash EG Walking or talking

Does not reach conscious awarenessMuscle synergy or coordination monitoredImportant in running speaking - all fluid

movements

THE CEREBELLUM AND BASAL GANGLIA COORDINATE MOVEMENTS

THE CEREBELLUM IS INVOLVED IN PLANNING COORDINATION AND POSTURE

ANTERIOR AND POSTERIOR LOBES INVOLVED IN LIMB MOVEMENT

FLOCCULONODULAR LOBE IS INVOLVED IN EQUILIBRIUM AND POSTURE

5

Function of Cerebellum

Error Control Device - Monitor Quality Controlndash Monitors outputs to muscles from motor cortex and

sensory signals from receptorsndash Compares the efferent project plan with execution

at motor action sitendash Considers related factors and makes adjustments

Evolution

3 main stages based on the complexity of movement

Archecerebellum ndash balancePaleocerebellum ndash posture locomotionNeocerebellum ndash programming skilled and

learned movement

6

7

tentorium cerebelli

tent of the cerebellum dura mater that

separates the cerebellum from the inferior portion of the occipital lobes

8

Posterior Cranial Fossa

Fossa is a depression or cavity in the bone

Cerebellum pons and medulla oblongata sit in the Posterior cranial fossa

9

Cerebellar Anatomy

Located dorsal to pons and medulla

In posterior fossa under tentorium cerebelli

Lobesndash Floccular Nodular(small

fluffy mass)ndash Anteriorndash Posterior

Seen from feet

Posterior lobe (I)

Anterior lobe (H)

11

Flattened Cerebellum

Longitudinally separated into hemispheres and corticesndash Median (Vermal)

Vermis=worm

ndash Paramedian (Paravermal

ndash Lateral

12

Cerebellum

Median Paramedian PrimaryFissure

PosteriorSuperiorFissure

HorizontalFissure

Posterolateral Fissure

Prepyramidal Fissure

13

Transverse Cerebellar Regions

1 Floccular nodular lobe (Archicerebellum )ndash Oldest related to vestibular part of VIIIndash Regulates equilibrium through vestibulospinal tract

2 Anterior lobe (Paleocerebellum)ndash Rostral to Primary Fissurendash General Sensory Receptorsndash Concerned with muscle tone and walking

3 Posterior lobe (Neocerebellum)ndash Newest and Largest Receives afferent projections from contralateral

sensorimotor cortexndash Projects to contralateral motor cortexndash Functions in coordination of fine and skilled movements

14

Longitudinal Cerebellar Regions

Vermisndash Contributes to body posture

Paravermal regionndash Regulates movements of ipsilateral extremities

(eg walking)

Lateral Zonendash Regulates skilled movements of ipsilateral

extremity (eg tying your shoe)

15

Cerebellar Connection

Three Peduncles1 Inferior ndash afferent mediate sensorimotor input to the

cerebellum2 Middle ndash afferent same as above3 Superior ndash efferent transmit output from the cerebellum to

the brainstem and on to the thalamus motor cortex and spinal cord

Varied afferents to Cerebellum ndash spinal cordndash brainstem ndash motor cortex

AfferenetEfferent Ratio = 401ndash For each going from cerebellum to body 40 coming in

Cerebellar Nuclei

16

Dentate NucleusNeocerebellum

Paleocerebellum Globose amp emboliform nuclei

Archecerebellum

Fastigeal Nucleus

Vestibular Nucleus

17

Cerebellar Nuclei (Nuclei = deep cluster of neurons)

Dentate nucleusndash Largest communicates through cerebellar peduncle ndash Carries information important for coordination of limb

movements (along with the motor cortex and basal ganglia)

Emboliform nucleus (medial side of the nucleus dentatus)ndash Regulates movements of ipsilateral extremity

Globose nucleusndash Regulates movements of ipsilateral extremity

Fastigial nucleusndash Regulates body posturendash Is related to the flocculo nodular lobe

18

Dentate Nucleus

Pons

PontineProjections

DentateNucleus

SuperiorCerebellarPeduncle

19

Somatotopic Organization

Tactile informationndash Ipsilateral anterior lobule ndash Bilateral paramedian lobulesndash Cerebral Cortex and

Cerebellum have similar representations

Motor representationndash Same area as sensory

mappingndash May have auditory and visual

processing

20

Afferent Pathways (Inferior)

Vestibulocerebellar Tractndash Info From Semicircular Canals Through Inferior

Pedunclendash Maintains Upright Posture

Dorsal Spinocerebellar Tractndash Info From Reticular Nuclei (involved in regulation

of sleep respiration heartbeat etc)ndash Unconscious Proprioception From Muscle

Spindles Golgi Tendons and Tactile Receptors

21

Afferent and Efferent Projections

Superior CerebellarPeduncle

Red nucleus

Thalamus

Middle CerebellarPeduncle (pontocerebellar fibers)

Inferior Cerebellar Nucleus(olivocerebellar fibers)

22

Afferent Pathways (Middle)

Info From Pontine Nuclei From Opposite Cerebral Cortex Visual and Auditory Inputs

To Opposite Cerebellar Hemisphere

Afferent Connections amp Functions

23

Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve

Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in

located posteriorly in the superior vermis

Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate

24

Efferent Pathways

Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex

Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium

25

Cerebellar Cortex

Structured in Three Parallel Layersndash Molecularndash Purkinje

Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex

ndash GranularHave Mossy Fiber Axons to Purkinje Axons

CELL TYPES AND CIRCUITS IN THE CEREBELLUM

Cerebellar Cortex

Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell

Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely

branched dendrites (400 000 synapses)

Granular cells- vast numbers of small neurons with axons ascending into the molecular layer

27

PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES

TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS

OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS

CEREBELLAR LESIONS

IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN

COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE

ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS

PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA

30

Clinical Considerations

Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia

Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)

ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody

Overview of Hypothalamus

Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures

31

Functions of Hypothalamus

Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious

ndash Temperature regulationndash Feeding

32

33

Regulates Mechanism by

Receiving sensory information from all areas of the body

Comparing sensory information with biological set points

Adjusting the system to restore the body balance when deviations from biological set points occur

Example Set pointsndash Blood sugar Hormone levels Temperature

Sodium34

Autonomic nervous system regulationInfluences PSNS through projections to brainstem

PSNS nuclei

Posterior area influences SNS through projections to the lateral gray horn

35

Hormone ProductionMagnocellular regions of the supraoptic and

paraventricular nuclei produce oxytocin and vassopressin (ADH)

Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700

Released in circulationDamage to supraoptic n diabetes insipidusrArr

36

Hormone Production

ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis

37

Cercadian rhythm regulation

ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland

38

Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills

Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating

39

3

Cerebellum

50 of brainrsquos neurons 10 of volumeCan change movements as necessary

ndash EG Walking or talking

Does not reach conscious awarenessMuscle synergy or coordination monitoredImportant in running speaking - all fluid

movements

THE CEREBELLUM AND BASAL GANGLIA COORDINATE MOVEMENTS

THE CEREBELLUM IS INVOLVED IN PLANNING COORDINATION AND POSTURE

ANTERIOR AND POSTERIOR LOBES INVOLVED IN LIMB MOVEMENT

FLOCCULONODULAR LOBE IS INVOLVED IN EQUILIBRIUM AND POSTURE

5

Function of Cerebellum

Error Control Device - Monitor Quality Controlndash Monitors outputs to muscles from motor cortex and

sensory signals from receptorsndash Compares the efferent project plan with execution

at motor action sitendash Considers related factors and makes adjustments

Evolution

3 main stages based on the complexity of movement

Archecerebellum ndash balancePaleocerebellum ndash posture locomotionNeocerebellum ndash programming skilled and

learned movement

6

7

tentorium cerebelli

tent of the cerebellum dura mater that

separates the cerebellum from the inferior portion of the occipital lobes

8

Posterior Cranial Fossa

Fossa is a depression or cavity in the bone

Cerebellum pons and medulla oblongata sit in the Posterior cranial fossa

9

Cerebellar Anatomy

Located dorsal to pons and medulla

In posterior fossa under tentorium cerebelli

Lobesndash Floccular Nodular(small

fluffy mass)ndash Anteriorndash Posterior

Seen from feet

Posterior lobe (I)

Anterior lobe (H)

11

Flattened Cerebellum

Longitudinally separated into hemispheres and corticesndash Median (Vermal)

Vermis=worm

ndash Paramedian (Paravermal

ndash Lateral

12

Cerebellum

Median Paramedian PrimaryFissure

PosteriorSuperiorFissure

HorizontalFissure

Posterolateral Fissure

Prepyramidal Fissure

13

Transverse Cerebellar Regions

1 Floccular nodular lobe (Archicerebellum )ndash Oldest related to vestibular part of VIIIndash Regulates equilibrium through vestibulospinal tract

2 Anterior lobe (Paleocerebellum)ndash Rostral to Primary Fissurendash General Sensory Receptorsndash Concerned with muscle tone and walking

3 Posterior lobe (Neocerebellum)ndash Newest and Largest Receives afferent projections from contralateral

sensorimotor cortexndash Projects to contralateral motor cortexndash Functions in coordination of fine and skilled movements

14

Longitudinal Cerebellar Regions

Vermisndash Contributes to body posture

Paravermal regionndash Regulates movements of ipsilateral extremities

(eg walking)

Lateral Zonendash Regulates skilled movements of ipsilateral

extremity (eg tying your shoe)

15

Cerebellar Connection

Three Peduncles1 Inferior ndash afferent mediate sensorimotor input to the

cerebellum2 Middle ndash afferent same as above3 Superior ndash efferent transmit output from the cerebellum to

the brainstem and on to the thalamus motor cortex and spinal cord

Varied afferents to Cerebellum ndash spinal cordndash brainstem ndash motor cortex

AfferenetEfferent Ratio = 401ndash For each going from cerebellum to body 40 coming in

Cerebellar Nuclei

16

Dentate NucleusNeocerebellum

Paleocerebellum Globose amp emboliform nuclei

Archecerebellum

Fastigeal Nucleus

Vestibular Nucleus

17

Cerebellar Nuclei (Nuclei = deep cluster of neurons)

Dentate nucleusndash Largest communicates through cerebellar peduncle ndash Carries information important for coordination of limb

movements (along with the motor cortex and basal ganglia)

Emboliform nucleus (medial side of the nucleus dentatus)ndash Regulates movements of ipsilateral extremity

Globose nucleusndash Regulates movements of ipsilateral extremity

Fastigial nucleusndash Regulates body posturendash Is related to the flocculo nodular lobe

18

Dentate Nucleus

Pons

PontineProjections

DentateNucleus

SuperiorCerebellarPeduncle

19

Somatotopic Organization

Tactile informationndash Ipsilateral anterior lobule ndash Bilateral paramedian lobulesndash Cerebral Cortex and

Cerebellum have similar representations

Motor representationndash Same area as sensory

mappingndash May have auditory and visual

processing

20

Afferent Pathways (Inferior)

Vestibulocerebellar Tractndash Info From Semicircular Canals Through Inferior

Pedunclendash Maintains Upright Posture

Dorsal Spinocerebellar Tractndash Info From Reticular Nuclei (involved in regulation

of sleep respiration heartbeat etc)ndash Unconscious Proprioception From Muscle

Spindles Golgi Tendons and Tactile Receptors

21

Afferent and Efferent Projections

Superior CerebellarPeduncle

Red nucleus

Thalamus

Middle CerebellarPeduncle (pontocerebellar fibers)

Inferior Cerebellar Nucleus(olivocerebellar fibers)

22

Afferent Pathways (Middle)

Info From Pontine Nuclei From Opposite Cerebral Cortex Visual and Auditory Inputs

To Opposite Cerebellar Hemisphere

Afferent Connections amp Functions

23

Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve

Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in

located posteriorly in the superior vermis

Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate

24

Efferent Pathways

Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex

Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium

25

Cerebellar Cortex

Structured in Three Parallel Layersndash Molecularndash Purkinje

Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex

ndash GranularHave Mossy Fiber Axons to Purkinje Axons

CELL TYPES AND CIRCUITS IN THE CEREBELLUM

Cerebellar Cortex

Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell

Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely

branched dendrites (400 000 synapses)

Granular cells- vast numbers of small neurons with axons ascending into the molecular layer

27

PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES

TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS

OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS

CEREBELLAR LESIONS

IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN

COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE

ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS

PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA

30

Clinical Considerations

Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia

Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)

ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody

Overview of Hypothalamus

Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures

31

Functions of Hypothalamus

Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious

ndash Temperature regulationndash Feeding

32

33

Regulates Mechanism by

Receiving sensory information from all areas of the body

Comparing sensory information with biological set points

Adjusting the system to restore the body balance when deviations from biological set points occur

Example Set pointsndash Blood sugar Hormone levels Temperature

Sodium34

Autonomic nervous system regulationInfluences PSNS through projections to brainstem

PSNS nuclei

Posterior area influences SNS through projections to the lateral gray horn

35

Hormone ProductionMagnocellular regions of the supraoptic and

paraventricular nuclei produce oxytocin and vassopressin (ADH)

Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700

Released in circulationDamage to supraoptic n diabetes insipidusrArr

36

Hormone Production

ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis

37

Cercadian rhythm regulation

ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland

38

Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills

Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating

39

THE CEREBELLUM AND BASAL GANGLIA COORDINATE MOVEMENTS

THE CEREBELLUM IS INVOLVED IN PLANNING COORDINATION AND POSTURE

ANTERIOR AND POSTERIOR LOBES INVOLVED IN LIMB MOVEMENT

FLOCCULONODULAR LOBE IS INVOLVED IN EQUILIBRIUM AND POSTURE

5

Function of Cerebellum

Error Control Device - Monitor Quality Controlndash Monitors outputs to muscles from motor cortex and

sensory signals from receptorsndash Compares the efferent project plan with execution

at motor action sitendash Considers related factors and makes adjustments

Evolution

3 main stages based on the complexity of movement

Archecerebellum ndash balancePaleocerebellum ndash posture locomotionNeocerebellum ndash programming skilled and

learned movement

6

7

tentorium cerebelli

tent of the cerebellum dura mater that

separates the cerebellum from the inferior portion of the occipital lobes

8

Posterior Cranial Fossa

Fossa is a depression or cavity in the bone

Cerebellum pons and medulla oblongata sit in the Posterior cranial fossa

9

Cerebellar Anatomy

Located dorsal to pons and medulla

In posterior fossa under tentorium cerebelli

Lobesndash Floccular Nodular(small

fluffy mass)ndash Anteriorndash Posterior

Seen from feet

Posterior lobe (I)

Anterior lobe (H)

11

Flattened Cerebellum

Longitudinally separated into hemispheres and corticesndash Median (Vermal)

Vermis=worm

ndash Paramedian (Paravermal

ndash Lateral

12

Cerebellum

Median Paramedian PrimaryFissure

PosteriorSuperiorFissure

HorizontalFissure

Posterolateral Fissure

Prepyramidal Fissure

13

Transverse Cerebellar Regions

1 Floccular nodular lobe (Archicerebellum )ndash Oldest related to vestibular part of VIIIndash Regulates equilibrium through vestibulospinal tract

2 Anterior lobe (Paleocerebellum)ndash Rostral to Primary Fissurendash General Sensory Receptorsndash Concerned with muscle tone and walking

3 Posterior lobe (Neocerebellum)ndash Newest and Largest Receives afferent projections from contralateral

sensorimotor cortexndash Projects to contralateral motor cortexndash Functions in coordination of fine and skilled movements

14

Longitudinal Cerebellar Regions

Vermisndash Contributes to body posture

Paravermal regionndash Regulates movements of ipsilateral extremities

(eg walking)

Lateral Zonendash Regulates skilled movements of ipsilateral

extremity (eg tying your shoe)

15

Cerebellar Connection

Three Peduncles1 Inferior ndash afferent mediate sensorimotor input to the

cerebellum2 Middle ndash afferent same as above3 Superior ndash efferent transmit output from the cerebellum to

the brainstem and on to the thalamus motor cortex and spinal cord

Varied afferents to Cerebellum ndash spinal cordndash brainstem ndash motor cortex

AfferenetEfferent Ratio = 401ndash For each going from cerebellum to body 40 coming in

Cerebellar Nuclei

16

Dentate NucleusNeocerebellum

Paleocerebellum Globose amp emboliform nuclei

Archecerebellum

Fastigeal Nucleus

Vestibular Nucleus

17

Cerebellar Nuclei (Nuclei = deep cluster of neurons)

Dentate nucleusndash Largest communicates through cerebellar peduncle ndash Carries information important for coordination of limb

movements (along with the motor cortex and basal ganglia)

Emboliform nucleus (medial side of the nucleus dentatus)ndash Regulates movements of ipsilateral extremity

Globose nucleusndash Regulates movements of ipsilateral extremity

Fastigial nucleusndash Regulates body posturendash Is related to the flocculo nodular lobe

18

Dentate Nucleus

Pons

PontineProjections

DentateNucleus

SuperiorCerebellarPeduncle

19

Somatotopic Organization

Tactile informationndash Ipsilateral anterior lobule ndash Bilateral paramedian lobulesndash Cerebral Cortex and

Cerebellum have similar representations

Motor representationndash Same area as sensory

mappingndash May have auditory and visual

processing

20

Afferent Pathways (Inferior)

Vestibulocerebellar Tractndash Info From Semicircular Canals Through Inferior

Pedunclendash Maintains Upright Posture

Dorsal Spinocerebellar Tractndash Info From Reticular Nuclei (involved in regulation

of sleep respiration heartbeat etc)ndash Unconscious Proprioception From Muscle

Spindles Golgi Tendons and Tactile Receptors

21

Afferent and Efferent Projections

Superior CerebellarPeduncle

Red nucleus

Thalamus

Middle CerebellarPeduncle (pontocerebellar fibers)

Inferior Cerebellar Nucleus(olivocerebellar fibers)

22

Afferent Pathways (Middle)

Info From Pontine Nuclei From Opposite Cerebral Cortex Visual and Auditory Inputs

To Opposite Cerebellar Hemisphere

Afferent Connections amp Functions

23

Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve

Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in

located posteriorly in the superior vermis

Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate

24

Efferent Pathways

Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex

Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium

25

Cerebellar Cortex

Structured in Three Parallel Layersndash Molecularndash Purkinje

Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex

ndash GranularHave Mossy Fiber Axons to Purkinje Axons

CELL TYPES AND CIRCUITS IN THE CEREBELLUM

Cerebellar Cortex

Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell

Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely

branched dendrites (400 000 synapses)

Granular cells- vast numbers of small neurons with axons ascending into the molecular layer

27

PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES

TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS

OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS

CEREBELLAR LESIONS

IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN

COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE

ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS

PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA

30

Clinical Considerations

Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia

Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)

ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody

Overview of Hypothalamus

Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures

31

Functions of Hypothalamus

Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious

ndash Temperature regulationndash Feeding

32

33

Regulates Mechanism by

Receiving sensory information from all areas of the body

Comparing sensory information with biological set points

Adjusting the system to restore the body balance when deviations from biological set points occur

Example Set pointsndash Blood sugar Hormone levels Temperature

Sodium34

Autonomic nervous system regulationInfluences PSNS through projections to brainstem

PSNS nuclei

Posterior area influences SNS through projections to the lateral gray horn

35

Hormone ProductionMagnocellular regions of the supraoptic and

paraventricular nuclei produce oxytocin and vassopressin (ADH)

Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700

Released in circulationDamage to supraoptic n diabetes insipidusrArr

36

Hormone Production

ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis

37

Cercadian rhythm regulation

ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland

38

Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills

Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating

39

5

Function of Cerebellum

Error Control Device - Monitor Quality Controlndash Monitors outputs to muscles from motor cortex and

sensory signals from receptorsndash Compares the efferent project plan with execution

at motor action sitendash Considers related factors and makes adjustments

Evolution

3 main stages based on the complexity of movement

Archecerebellum ndash balancePaleocerebellum ndash posture locomotionNeocerebellum ndash programming skilled and

learned movement

6

7

tentorium cerebelli

tent of the cerebellum dura mater that

separates the cerebellum from the inferior portion of the occipital lobes

8

Posterior Cranial Fossa

Fossa is a depression or cavity in the bone

Cerebellum pons and medulla oblongata sit in the Posterior cranial fossa

9

Cerebellar Anatomy

Located dorsal to pons and medulla

In posterior fossa under tentorium cerebelli

Lobesndash Floccular Nodular(small

fluffy mass)ndash Anteriorndash Posterior

Seen from feet

Posterior lobe (I)

Anterior lobe (H)

11

Flattened Cerebellum

Longitudinally separated into hemispheres and corticesndash Median (Vermal)

Vermis=worm

ndash Paramedian (Paravermal

ndash Lateral

12

Cerebellum

Median Paramedian PrimaryFissure

PosteriorSuperiorFissure

HorizontalFissure

Posterolateral Fissure

Prepyramidal Fissure

13

Transverse Cerebellar Regions

1 Floccular nodular lobe (Archicerebellum )ndash Oldest related to vestibular part of VIIIndash Regulates equilibrium through vestibulospinal tract

2 Anterior lobe (Paleocerebellum)ndash Rostral to Primary Fissurendash General Sensory Receptorsndash Concerned with muscle tone and walking

3 Posterior lobe (Neocerebellum)ndash Newest and Largest Receives afferent projections from contralateral

sensorimotor cortexndash Projects to contralateral motor cortexndash Functions in coordination of fine and skilled movements

14

Longitudinal Cerebellar Regions

Vermisndash Contributes to body posture

Paravermal regionndash Regulates movements of ipsilateral extremities

(eg walking)

Lateral Zonendash Regulates skilled movements of ipsilateral

extremity (eg tying your shoe)

15

Cerebellar Connection

Three Peduncles1 Inferior ndash afferent mediate sensorimotor input to the

cerebellum2 Middle ndash afferent same as above3 Superior ndash efferent transmit output from the cerebellum to

the brainstem and on to the thalamus motor cortex and spinal cord

Varied afferents to Cerebellum ndash spinal cordndash brainstem ndash motor cortex

AfferenetEfferent Ratio = 401ndash For each going from cerebellum to body 40 coming in

Cerebellar Nuclei

16

Dentate NucleusNeocerebellum

Paleocerebellum Globose amp emboliform nuclei

Archecerebellum

Fastigeal Nucleus

Vestibular Nucleus

17

Cerebellar Nuclei (Nuclei = deep cluster of neurons)

Dentate nucleusndash Largest communicates through cerebellar peduncle ndash Carries information important for coordination of limb

movements (along with the motor cortex and basal ganglia)

Emboliform nucleus (medial side of the nucleus dentatus)ndash Regulates movements of ipsilateral extremity

Globose nucleusndash Regulates movements of ipsilateral extremity

Fastigial nucleusndash Regulates body posturendash Is related to the flocculo nodular lobe

18

Dentate Nucleus

Pons

PontineProjections

DentateNucleus

SuperiorCerebellarPeduncle

19

Somatotopic Organization

Tactile informationndash Ipsilateral anterior lobule ndash Bilateral paramedian lobulesndash Cerebral Cortex and

Cerebellum have similar representations

Motor representationndash Same area as sensory

mappingndash May have auditory and visual

processing

20

Afferent Pathways (Inferior)

Vestibulocerebellar Tractndash Info From Semicircular Canals Through Inferior

Pedunclendash Maintains Upright Posture

Dorsal Spinocerebellar Tractndash Info From Reticular Nuclei (involved in regulation

of sleep respiration heartbeat etc)ndash Unconscious Proprioception From Muscle

Spindles Golgi Tendons and Tactile Receptors

21

Afferent and Efferent Projections

Superior CerebellarPeduncle

Red nucleus

Thalamus

Middle CerebellarPeduncle (pontocerebellar fibers)

Inferior Cerebellar Nucleus(olivocerebellar fibers)

22

Afferent Pathways (Middle)

Info From Pontine Nuclei From Opposite Cerebral Cortex Visual and Auditory Inputs

To Opposite Cerebellar Hemisphere

Afferent Connections amp Functions

23

Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve

Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in

located posteriorly in the superior vermis

Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate

24

Efferent Pathways

Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex

Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium

25

Cerebellar Cortex

Structured in Three Parallel Layersndash Molecularndash Purkinje

Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex

ndash GranularHave Mossy Fiber Axons to Purkinje Axons

CELL TYPES AND CIRCUITS IN THE CEREBELLUM

Cerebellar Cortex

Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell

Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely

branched dendrites (400 000 synapses)

Granular cells- vast numbers of small neurons with axons ascending into the molecular layer

27

PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES

TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS

OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS

CEREBELLAR LESIONS

IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN

COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE

ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS

PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA

30

Clinical Considerations

Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia

Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)

ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody

Overview of Hypothalamus

Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures

31

Functions of Hypothalamus

Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious

ndash Temperature regulationndash Feeding

32

33

Regulates Mechanism by

Receiving sensory information from all areas of the body

Comparing sensory information with biological set points

Adjusting the system to restore the body balance when deviations from biological set points occur

Example Set pointsndash Blood sugar Hormone levels Temperature

Sodium34

Autonomic nervous system regulationInfluences PSNS through projections to brainstem

PSNS nuclei

Posterior area influences SNS through projections to the lateral gray horn

35

Hormone ProductionMagnocellular regions of the supraoptic and

paraventricular nuclei produce oxytocin and vassopressin (ADH)

Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700

Released in circulationDamage to supraoptic n diabetes insipidusrArr

36

Hormone Production

ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis

37

Cercadian rhythm regulation

ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland

38

Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills

Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating

39

Evolution

3 main stages based on the complexity of movement

Archecerebellum ndash balancePaleocerebellum ndash posture locomotionNeocerebellum ndash programming skilled and

learned movement

6

7

tentorium cerebelli

tent of the cerebellum dura mater that

separates the cerebellum from the inferior portion of the occipital lobes

8

Posterior Cranial Fossa

Fossa is a depression or cavity in the bone

Cerebellum pons and medulla oblongata sit in the Posterior cranial fossa

9

Cerebellar Anatomy

Located dorsal to pons and medulla

In posterior fossa under tentorium cerebelli

Lobesndash Floccular Nodular(small

fluffy mass)ndash Anteriorndash Posterior

Seen from feet

Posterior lobe (I)

Anterior lobe (H)

11

Flattened Cerebellum

Longitudinally separated into hemispheres and corticesndash Median (Vermal)

Vermis=worm

ndash Paramedian (Paravermal

ndash Lateral

12

Cerebellum

Median Paramedian PrimaryFissure

PosteriorSuperiorFissure

HorizontalFissure

Posterolateral Fissure

Prepyramidal Fissure

13

Transverse Cerebellar Regions

1 Floccular nodular lobe (Archicerebellum )ndash Oldest related to vestibular part of VIIIndash Regulates equilibrium through vestibulospinal tract

2 Anterior lobe (Paleocerebellum)ndash Rostral to Primary Fissurendash General Sensory Receptorsndash Concerned with muscle tone and walking

3 Posterior lobe (Neocerebellum)ndash Newest and Largest Receives afferent projections from contralateral

sensorimotor cortexndash Projects to contralateral motor cortexndash Functions in coordination of fine and skilled movements

14

Longitudinal Cerebellar Regions

Vermisndash Contributes to body posture

Paravermal regionndash Regulates movements of ipsilateral extremities

(eg walking)

Lateral Zonendash Regulates skilled movements of ipsilateral

extremity (eg tying your shoe)

15

Cerebellar Connection

Three Peduncles1 Inferior ndash afferent mediate sensorimotor input to the

cerebellum2 Middle ndash afferent same as above3 Superior ndash efferent transmit output from the cerebellum to

the brainstem and on to the thalamus motor cortex and spinal cord

Varied afferents to Cerebellum ndash spinal cordndash brainstem ndash motor cortex

AfferenetEfferent Ratio = 401ndash For each going from cerebellum to body 40 coming in

Cerebellar Nuclei

16

Dentate NucleusNeocerebellum

Paleocerebellum Globose amp emboliform nuclei

Archecerebellum

Fastigeal Nucleus

Vestibular Nucleus

17

Cerebellar Nuclei (Nuclei = deep cluster of neurons)

Dentate nucleusndash Largest communicates through cerebellar peduncle ndash Carries information important for coordination of limb

movements (along with the motor cortex and basal ganglia)

Emboliform nucleus (medial side of the nucleus dentatus)ndash Regulates movements of ipsilateral extremity

Globose nucleusndash Regulates movements of ipsilateral extremity

Fastigial nucleusndash Regulates body posturendash Is related to the flocculo nodular lobe

18

Dentate Nucleus

Pons

PontineProjections

DentateNucleus

SuperiorCerebellarPeduncle

19

Somatotopic Organization

Tactile informationndash Ipsilateral anterior lobule ndash Bilateral paramedian lobulesndash Cerebral Cortex and

Cerebellum have similar representations

Motor representationndash Same area as sensory

mappingndash May have auditory and visual

processing

20

Afferent Pathways (Inferior)

Vestibulocerebellar Tractndash Info From Semicircular Canals Through Inferior

Pedunclendash Maintains Upright Posture

Dorsal Spinocerebellar Tractndash Info From Reticular Nuclei (involved in regulation

of sleep respiration heartbeat etc)ndash Unconscious Proprioception From Muscle

Spindles Golgi Tendons and Tactile Receptors

21

Afferent and Efferent Projections

Superior CerebellarPeduncle

Red nucleus

Thalamus

Middle CerebellarPeduncle (pontocerebellar fibers)

Inferior Cerebellar Nucleus(olivocerebellar fibers)

22

Afferent Pathways (Middle)

Info From Pontine Nuclei From Opposite Cerebral Cortex Visual and Auditory Inputs

To Opposite Cerebellar Hemisphere

Afferent Connections amp Functions

23

Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve

Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in

located posteriorly in the superior vermis

Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate

24

Efferent Pathways

Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex

Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium

25

Cerebellar Cortex

Structured in Three Parallel Layersndash Molecularndash Purkinje

Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex

ndash GranularHave Mossy Fiber Axons to Purkinje Axons

CELL TYPES AND CIRCUITS IN THE CEREBELLUM

Cerebellar Cortex

Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell

Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely

branched dendrites (400 000 synapses)

Granular cells- vast numbers of small neurons with axons ascending into the molecular layer

27

PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES

TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS

OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS

CEREBELLAR LESIONS

IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN

COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE

ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS

PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA

30

Clinical Considerations

Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia

Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)

ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody

Overview of Hypothalamus

Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures

31

Functions of Hypothalamus

Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious

ndash Temperature regulationndash Feeding

32

33

Regulates Mechanism by

Receiving sensory information from all areas of the body

Comparing sensory information with biological set points

Adjusting the system to restore the body balance when deviations from biological set points occur

Example Set pointsndash Blood sugar Hormone levels Temperature

Sodium34

Autonomic nervous system regulationInfluences PSNS through projections to brainstem

PSNS nuclei

Posterior area influences SNS through projections to the lateral gray horn

35

Hormone ProductionMagnocellular regions of the supraoptic and

paraventricular nuclei produce oxytocin and vassopressin (ADH)

Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700

Released in circulationDamage to supraoptic n diabetes insipidusrArr

36

Hormone Production

ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis

37

Cercadian rhythm regulation

ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland

38

Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills

Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating

39

7

tentorium cerebelli

tent of the cerebellum dura mater that

separates the cerebellum from the inferior portion of the occipital lobes

8

Posterior Cranial Fossa

Fossa is a depression or cavity in the bone

Cerebellum pons and medulla oblongata sit in the Posterior cranial fossa

9

Cerebellar Anatomy

Located dorsal to pons and medulla

In posterior fossa under tentorium cerebelli

Lobesndash Floccular Nodular(small

fluffy mass)ndash Anteriorndash Posterior

Seen from feet

Posterior lobe (I)

Anterior lobe (H)

11

Flattened Cerebellum

Longitudinally separated into hemispheres and corticesndash Median (Vermal)

Vermis=worm

ndash Paramedian (Paravermal

ndash Lateral

12

Cerebellum

Median Paramedian PrimaryFissure

PosteriorSuperiorFissure

HorizontalFissure

Posterolateral Fissure

Prepyramidal Fissure

13

Transverse Cerebellar Regions

1 Floccular nodular lobe (Archicerebellum )ndash Oldest related to vestibular part of VIIIndash Regulates equilibrium through vestibulospinal tract

2 Anterior lobe (Paleocerebellum)ndash Rostral to Primary Fissurendash General Sensory Receptorsndash Concerned with muscle tone and walking

3 Posterior lobe (Neocerebellum)ndash Newest and Largest Receives afferent projections from contralateral

sensorimotor cortexndash Projects to contralateral motor cortexndash Functions in coordination of fine and skilled movements

14

Longitudinal Cerebellar Regions

Vermisndash Contributes to body posture

Paravermal regionndash Regulates movements of ipsilateral extremities

(eg walking)

Lateral Zonendash Regulates skilled movements of ipsilateral

extremity (eg tying your shoe)

15

Cerebellar Connection

Three Peduncles1 Inferior ndash afferent mediate sensorimotor input to the

cerebellum2 Middle ndash afferent same as above3 Superior ndash efferent transmit output from the cerebellum to

the brainstem and on to the thalamus motor cortex and spinal cord

Varied afferents to Cerebellum ndash spinal cordndash brainstem ndash motor cortex

AfferenetEfferent Ratio = 401ndash For each going from cerebellum to body 40 coming in

Cerebellar Nuclei

16

Dentate NucleusNeocerebellum

Paleocerebellum Globose amp emboliform nuclei

Archecerebellum

Fastigeal Nucleus

Vestibular Nucleus

17

Cerebellar Nuclei (Nuclei = deep cluster of neurons)

Dentate nucleusndash Largest communicates through cerebellar peduncle ndash Carries information important for coordination of limb

movements (along with the motor cortex and basal ganglia)

Emboliform nucleus (medial side of the nucleus dentatus)ndash Regulates movements of ipsilateral extremity

Globose nucleusndash Regulates movements of ipsilateral extremity

Fastigial nucleusndash Regulates body posturendash Is related to the flocculo nodular lobe

18

Dentate Nucleus

Pons

PontineProjections

DentateNucleus

SuperiorCerebellarPeduncle

19

Somatotopic Organization

Tactile informationndash Ipsilateral anterior lobule ndash Bilateral paramedian lobulesndash Cerebral Cortex and

Cerebellum have similar representations

Motor representationndash Same area as sensory

mappingndash May have auditory and visual

processing

20

Afferent Pathways (Inferior)

Vestibulocerebellar Tractndash Info From Semicircular Canals Through Inferior

Pedunclendash Maintains Upright Posture

Dorsal Spinocerebellar Tractndash Info From Reticular Nuclei (involved in regulation

of sleep respiration heartbeat etc)ndash Unconscious Proprioception From Muscle

Spindles Golgi Tendons and Tactile Receptors

21

Afferent and Efferent Projections

Superior CerebellarPeduncle

Red nucleus

Thalamus

Middle CerebellarPeduncle (pontocerebellar fibers)

Inferior Cerebellar Nucleus(olivocerebellar fibers)

22

Afferent Pathways (Middle)

Info From Pontine Nuclei From Opposite Cerebral Cortex Visual and Auditory Inputs

To Opposite Cerebellar Hemisphere

Afferent Connections amp Functions

23

Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve

Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in

located posteriorly in the superior vermis

Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate

24

Efferent Pathways

Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex

Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium

25

Cerebellar Cortex

Structured in Three Parallel Layersndash Molecularndash Purkinje

Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex

ndash GranularHave Mossy Fiber Axons to Purkinje Axons

CELL TYPES AND CIRCUITS IN THE CEREBELLUM

Cerebellar Cortex

Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell

Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely

branched dendrites (400 000 synapses)

Granular cells- vast numbers of small neurons with axons ascending into the molecular layer

27

PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES

TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS

OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS

CEREBELLAR LESIONS

IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN

COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE

ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS

PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA

30

Clinical Considerations

Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia

Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)

ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody

Overview of Hypothalamus

Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures

31

Functions of Hypothalamus

Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious

ndash Temperature regulationndash Feeding

32

33

Regulates Mechanism by

Receiving sensory information from all areas of the body

Comparing sensory information with biological set points

Adjusting the system to restore the body balance when deviations from biological set points occur

Example Set pointsndash Blood sugar Hormone levels Temperature

Sodium34

Autonomic nervous system regulationInfluences PSNS through projections to brainstem

PSNS nuclei

Posterior area influences SNS through projections to the lateral gray horn

35

Hormone ProductionMagnocellular regions of the supraoptic and

paraventricular nuclei produce oxytocin and vassopressin (ADH)

Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700

Released in circulationDamage to supraoptic n diabetes insipidusrArr

36

Hormone Production

ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis

37

Cercadian rhythm regulation

ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland

38

Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills

Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating

39

8

Posterior Cranial Fossa

Fossa is a depression or cavity in the bone

Cerebellum pons and medulla oblongata sit in the Posterior cranial fossa

9

Cerebellar Anatomy

Located dorsal to pons and medulla

In posterior fossa under tentorium cerebelli

Lobesndash Floccular Nodular(small

fluffy mass)ndash Anteriorndash Posterior

Seen from feet

Posterior lobe (I)

Anterior lobe (H)

11

Flattened Cerebellum

Longitudinally separated into hemispheres and corticesndash Median (Vermal)

Vermis=worm

ndash Paramedian (Paravermal

ndash Lateral

12

Cerebellum

Median Paramedian PrimaryFissure

PosteriorSuperiorFissure

HorizontalFissure

Posterolateral Fissure

Prepyramidal Fissure

13

Transverse Cerebellar Regions

1 Floccular nodular lobe (Archicerebellum )ndash Oldest related to vestibular part of VIIIndash Regulates equilibrium through vestibulospinal tract

2 Anterior lobe (Paleocerebellum)ndash Rostral to Primary Fissurendash General Sensory Receptorsndash Concerned with muscle tone and walking

3 Posterior lobe (Neocerebellum)ndash Newest and Largest Receives afferent projections from contralateral

sensorimotor cortexndash Projects to contralateral motor cortexndash Functions in coordination of fine and skilled movements

14

Longitudinal Cerebellar Regions

Vermisndash Contributes to body posture

Paravermal regionndash Regulates movements of ipsilateral extremities

(eg walking)

Lateral Zonendash Regulates skilled movements of ipsilateral

extremity (eg tying your shoe)

15

Cerebellar Connection

Three Peduncles1 Inferior ndash afferent mediate sensorimotor input to the

cerebellum2 Middle ndash afferent same as above3 Superior ndash efferent transmit output from the cerebellum to

the brainstem and on to the thalamus motor cortex and spinal cord

Varied afferents to Cerebellum ndash spinal cordndash brainstem ndash motor cortex

AfferenetEfferent Ratio = 401ndash For each going from cerebellum to body 40 coming in

Cerebellar Nuclei

16

Dentate NucleusNeocerebellum

Paleocerebellum Globose amp emboliform nuclei

Archecerebellum

Fastigeal Nucleus

Vestibular Nucleus

17

Cerebellar Nuclei (Nuclei = deep cluster of neurons)

Dentate nucleusndash Largest communicates through cerebellar peduncle ndash Carries information important for coordination of limb

movements (along with the motor cortex and basal ganglia)

Emboliform nucleus (medial side of the nucleus dentatus)ndash Regulates movements of ipsilateral extremity

Globose nucleusndash Regulates movements of ipsilateral extremity

Fastigial nucleusndash Regulates body posturendash Is related to the flocculo nodular lobe

18

Dentate Nucleus

Pons

PontineProjections

DentateNucleus

SuperiorCerebellarPeduncle

19

Somatotopic Organization

Tactile informationndash Ipsilateral anterior lobule ndash Bilateral paramedian lobulesndash Cerebral Cortex and

Cerebellum have similar representations

Motor representationndash Same area as sensory

mappingndash May have auditory and visual

processing

20

Afferent Pathways (Inferior)

Vestibulocerebellar Tractndash Info From Semicircular Canals Through Inferior

Pedunclendash Maintains Upright Posture

Dorsal Spinocerebellar Tractndash Info From Reticular Nuclei (involved in regulation

of sleep respiration heartbeat etc)ndash Unconscious Proprioception From Muscle

Spindles Golgi Tendons and Tactile Receptors

21

Afferent and Efferent Projections

Superior CerebellarPeduncle

Red nucleus

Thalamus

Middle CerebellarPeduncle (pontocerebellar fibers)

Inferior Cerebellar Nucleus(olivocerebellar fibers)

22

Afferent Pathways (Middle)

Info From Pontine Nuclei From Opposite Cerebral Cortex Visual and Auditory Inputs

To Opposite Cerebellar Hemisphere

Afferent Connections amp Functions

23

Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve

Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in

located posteriorly in the superior vermis

Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate

24

Efferent Pathways

Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex

Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium

25

Cerebellar Cortex

Structured in Three Parallel Layersndash Molecularndash Purkinje

Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex

ndash GranularHave Mossy Fiber Axons to Purkinje Axons

CELL TYPES AND CIRCUITS IN THE CEREBELLUM

Cerebellar Cortex

Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell

Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely

branched dendrites (400 000 synapses)

Granular cells- vast numbers of small neurons with axons ascending into the molecular layer

27

PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES

TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS

OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS

CEREBELLAR LESIONS

IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN

COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE

ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS

PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA

30

Clinical Considerations

Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia

Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)

ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody

Overview of Hypothalamus

Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures

31

Functions of Hypothalamus

Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious

ndash Temperature regulationndash Feeding

32

33

Regulates Mechanism by

Receiving sensory information from all areas of the body

Comparing sensory information with biological set points

Adjusting the system to restore the body balance when deviations from biological set points occur

Example Set pointsndash Blood sugar Hormone levels Temperature

Sodium34

Autonomic nervous system regulationInfluences PSNS through projections to brainstem

PSNS nuclei

Posterior area influences SNS through projections to the lateral gray horn

35

Hormone ProductionMagnocellular regions of the supraoptic and

paraventricular nuclei produce oxytocin and vassopressin (ADH)

Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700

Released in circulationDamage to supraoptic n diabetes insipidusrArr

36

Hormone Production

ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis

37

Cercadian rhythm regulation

ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland

38

Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills

Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating

39

9

Cerebellar Anatomy

Located dorsal to pons and medulla

In posterior fossa under tentorium cerebelli

Lobesndash Floccular Nodular(small

fluffy mass)ndash Anteriorndash Posterior

Seen from feet

Posterior lobe (I)

Anterior lobe (H)

11

Flattened Cerebellum

Longitudinally separated into hemispheres and corticesndash Median (Vermal)

Vermis=worm

ndash Paramedian (Paravermal

ndash Lateral

12

Cerebellum

Median Paramedian PrimaryFissure

PosteriorSuperiorFissure

HorizontalFissure

Posterolateral Fissure

Prepyramidal Fissure

13

Transverse Cerebellar Regions

1 Floccular nodular lobe (Archicerebellum )ndash Oldest related to vestibular part of VIIIndash Regulates equilibrium through vestibulospinal tract

2 Anterior lobe (Paleocerebellum)ndash Rostral to Primary Fissurendash General Sensory Receptorsndash Concerned with muscle tone and walking

3 Posterior lobe (Neocerebellum)ndash Newest and Largest Receives afferent projections from contralateral

sensorimotor cortexndash Projects to contralateral motor cortexndash Functions in coordination of fine and skilled movements

14

Longitudinal Cerebellar Regions

Vermisndash Contributes to body posture

Paravermal regionndash Regulates movements of ipsilateral extremities

(eg walking)

Lateral Zonendash Regulates skilled movements of ipsilateral

extremity (eg tying your shoe)

15

Cerebellar Connection

Three Peduncles1 Inferior ndash afferent mediate sensorimotor input to the

cerebellum2 Middle ndash afferent same as above3 Superior ndash efferent transmit output from the cerebellum to

the brainstem and on to the thalamus motor cortex and spinal cord

Varied afferents to Cerebellum ndash spinal cordndash brainstem ndash motor cortex

AfferenetEfferent Ratio = 401ndash For each going from cerebellum to body 40 coming in

Cerebellar Nuclei

16

Dentate NucleusNeocerebellum

Paleocerebellum Globose amp emboliform nuclei

Archecerebellum

Fastigeal Nucleus

Vestibular Nucleus

17

Cerebellar Nuclei (Nuclei = deep cluster of neurons)

Dentate nucleusndash Largest communicates through cerebellar peduncle ndash Carries information important for coordination of limb

movements (along with the motor cortex and basal ganglia)

Emboliform nucleus (medial side of the nucleus dentatus)ndash Regulates movements of ipsilateral extremity

Globose nucleusndash Regulates movements of ipsilateral extremity

Fastigial nucleusndash Regulates body posturendash Is related to the flocculo nodular lobe

18

Dentate Nucleus

Pons

PontineProjections

DentateNucleus

SuperiorCerebellarPeduncle

19

Somatotopic Organization

Tactile informationndash Ipsilateral anterior lobule ndash Bilateral paramedian lobulesndash Cerebral Cortex and

Cerebellum have similar representations

Motor representationndash Same area as sensory

mappingndash May have auditory and visual

processing

20

Afferent Pathways (Inferior)

Vestibulocerebellar Tractndash Info From Semicircular Canals Through Inferior

Pedunclendash Maintains Upright Posture

Dorsal Spinocerebellar Tractndash Info From Reticular Nuclei (involved in regulation

of sleep respiration heartbeat etc)ndash Unconscious Proprioception From Muscle

Spindles Golgi Tendons and Tactile Receptors

21

Afferent and Efferent Projections

Superior CerebellarPeduncle

Red nucleus

Thalamus

Middle CerebellarPeduncle (pontocerebellar fibers)

Inferior Cerebellar Nucleus(olivocerebellar fibers)

22

Afferent Pathways (Middle)

Info From Pontine Nuclei From Opposite Cerebral Cortex Visual and Auditory Inputs

To Opposite Cerebellar Hemisphere

Afferent Connections amp Functions

23

Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve

Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in

located posteriorly in the superior vermis

Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate

24

Efferent Pathways

Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex

Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium

25

Cerebellar Cortex

Structured in Three Parallel Layersndash Molecularndash Purkinje

Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex

ndash GranularHave Mossy Fiber Axons to Purkinje Axons

CELL TYPES AND CIRCUITS IN THE CEREBELLUM

Cerebellar Cortex

Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell

Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely

branched dendrites (400 000 synapses)

Granular cells- vast numbers of small neurons with axons ascending into the molecular layer

27

PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES

TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS

OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS

CEREBELLAR LESIONS

IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN

COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE

ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS

PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA

30

Clinical Considerations

Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia

Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)

ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody

Overview of Hypothalamus

Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures

31

Functions of Hypothalamus

Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious

ndash Temperature regulationndash Feeding

32

33

Regulates Mechanism by

Receiving sensory information from all areas of the body

Comparing sensory information with biological set points

Adjusting the system to restore the body balance when deviations from biological set points occur

Example Set pointsndash Blood sugar Hormone levels Temperature

Sodium34

Autonomic nervous system regulationInfluences PSNS through projections to brainstem

PSNS nuclei

Posterior area influences SNS through projections to the lateral gray horn

35

Hormone ProductionMagnocellular regions of the supraoptic and

paraventricular nuclei produce oxytocin and vassopressin (ADH)

Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700

Released in circulationDamage to supraoptic n diabetes insipidusrArr

36

Hormone Production

ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis

37

Cercadian rhythm regulation

ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland

38

Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills

Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating

39

11

Flattened Cerebellum

Longitudinally separated into hemispheres and corticesndash Median (Vermal)

Vermis=worm

ndash Paramedian (Paravermal

ndash Lateral

12

Cerebellum

Median Paramedian PrimaryFissure

PosteriorSuperiorFissure

HorizontalFissure

Posterolateral Fissure

Prepyramidal Fissure

13

Transverse Cerebellar Regions

1 Floccular nodular lobe (Archicerebellum )ndash Oldest related to vestibular part of VIIIndash Regulates equilibrium through vestibulospinal tract

2 Anterior lobe (Paleocerebellum)ndash Rostral to Primary Fissurendash General Sensory Receptorsndash Concerned with muscle tone and walking

3 Posterior lobe (Neocerebellum)ndash Newest and Largest Receives afferent projections from contralateral

sensorimotor cortexndash Projects to contralateral motor cortexndash Functions in coordination of fine and skilled movements

14

Longitudinal Cerebellar Regions

Vermisndash Contributes to body posture

Paravermal regionndash Regulates movements of ipsilateral extremities

(eg walking)

Lateral Zonendash Regulates skilled movements of ipsilateral

extremity (eg tying your shoe)

15

Cerebellar Connection

Three Peduncles1 Inferior ndash afferent mediate sensorimotor input to the

cerebellum2 Middle ndash afferent same as above3 Superior ndash efferent transmit output from the cerebellum to

the brainstem and on to the thalamus motor cortex and spinal cord

Varied afferents to Cerebellum ndash spinal cordndash brainstem ndash motor cortex

AfferenetEfferent Ratio = 401ndash For each going from cerebellum to body 40 coming in

Cerebellar Nuclei

16

Dentate NucleusNeocerebellum

Paleocerebellum Globose amp emboliform nuclei

Archecerebellum

Fastigeal Nucleus

Vestibular Nucleus

17

Cerebellar Nuclei (Nuclei = deep cluster of neurons)

Dentate nucleusndash Largest communicates through cerebellar peduncle ndash Carries information important for coordination of limb

movements (along with the motor cortex and basal ganglia)

Emboliform nucleus (medial side of the nucleus dentatus)ndash Regulates movements of ipsilateral extremity

Globose nucleusndash Regulates movements of ipsilateral extremity

Fastigial nucleusndash Regulates body posturendash Is related to the flocculo nodular lobe

18

Dentate Nucleus

Pons

PontineProjections

DentateNucleus

SuperiorCerebellarPeduncle

19

Somatotopic Organization

Tactile informationndash Ipsilateral anterior lobule ndash Bilateral paramedian lobulesndash Cerebral Cortex and

Cerebellum have similar representations

Motor representationndash Same area as sensory

mappingndash May have auditory and visual

processing

20

Afferent Pathways (Inferior)

Vestibulocerebellar Tractndash Info From Semicircular Canals Through Inferior

Pedunclendash Maintains Upright Posture

Dorsal Spinocerebellar Tractndash Info From Reticular Nuclei (involved in regulation

of sleep respiration heartbeat etc)ndash Unconscious Proprioception From Muscle

Spindles Golgi Tendons and Tactile Receptors

21

Afferent and Efferent Projections

Superior CerebellarPeduncle

Red nucleus

Thalamus

Middle CerebellarPeduncle (pontocerebellar fibers)

Inferior Cerebellar Nucleus(olivocerebellar fibers)

22

Afferent Pathways (Middle)

Info From Pontine Nuclei From Opposite Cerebral Cortex Visual and Auditory Inputs

To Opposite Cerebellar Hemisphere

Afferent Connections amp Functions

23

Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve

Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in

located posteriorly in the superior vermis

Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate

24

Efferent Pathways

Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex

Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium

25

Cerebellar Cortex

Structured in Three Parallel Layersndash Molecularndash Purkinje

Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex

ndash GranularHave Mossy Fiber Axons to Purkinje Axons

CELL TYPES AND CIRCUITS IN THE CEREBELLUM

Cerebellar Cortex

Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell

Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely

branched dendrites (400 000 synapses)

Granular cells- vast numbers of small neurons with axons ascending into the molecular layer

27

PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES

TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS

OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS

CEREBELLAR LESIONS

IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN

COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE

ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS

PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA

30

Clinical Considerations

Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia

Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)

ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody

Overview of Hypothalamus

Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures

31

Functions of Hypothalamus

Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious

ndash Temperature regulationndash Feeding

32

33

Regulates Mechanism by

Receiving sensory information from all areas of the body

Comparing sensory information with biological set points

Adjusting the system to restore the body balance when deviations from biological set points occur

Example Set pointsndash Blood sugar Hormone levels Temperature

Sodium34

Autonomic nervous system regulationInfluences PSNS through projections to brainstem

PSNS nuclei

Posterior area influences SNS through projections to the lateral gray horn

35

Hormone ProductionMagnocellular regions of the supraoptic and

paraventricular nuclei produce oxytocin and vassopressin (ADH)

Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700

Released in circulationDamage to supraoptic n diabetes insipidusrArr

36

Hormone Production

ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis

37

Cercadian rhythm regulation

ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland

38

Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills

Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating

39

12

Cerebellum

Median Paramedian PrimaryFissure

PosteriorSuperiorFissure

HorizontalFissure

Posterolateral Fissure

Prepyramidal Fissure

13

Transverse Cerebellar Regions

1 Floccular nodular lobe (Archicerebellum )ndash Oldest related to vestibular part of VIIIndash Regulates equilibrium through vestibulospinal tract

2 Anterior lobe (Paleocerebellum)ndash Rostral to Primary Fissurendash General Sensory Receptorsndash Concerned with muscle tone and walking

3 Posterior lobe (Neocerebellum)ndash Newest and Largest Receives afferent projections from contralateral

sensorimotor cortexndash Projects to contralateral motor cortexndash Functions in coordination of fine and skilled movements

14

Longitudinal Cerebellar Regions

Vermisndash Contributes to body posture

Paravermal regionndash Regulates movements of ipsilateral extremities

(eg walking)

Lateral Zonendash Regulates skilled movements of ipsilateral

extremity (eg tying your shoe)

15

Cerebellar Connection

Three Peduncles1 Inferior ndash afferent mediate sensorimotor input to the

cerebellum2 Middle ndash afferent same as above3 Superior ndash efferent transmit output from the cerebellum to

the brainstem and on to the thalamus motor cortex and spinal cord

Varied afferents to Cerebellum ndash spinal cordndash brainstem ndash motor cortex

AfferenetEfferent Ratio = 401ndash For each going from cerebellum to body 40 coming in

Cerebellar Nuclei

16

Dentate NucleusNeocerebellum

Paleocerebellum Globose amp emboliform nuclei

Archecerebellum

Fastigeal Nucleus

Vestibular Nucleus

17

Cerebellar Nuclei (Nuclei = deep cluster of neurons)

Dentate nucleusndash Largest communicates through cerebellar peduncle ndash Carries information important for coordination of limb

movements (along with the motor cortex and basal ganglia)

Emboliform nucleus (medial side of the nucleus dentatus)ndash Regulates movements of ipsilateral extremity

Globose nucleusndash Regulates movements of ipsilateral extremity

Fastigial nucleusndash Regulates body posturendash Is related to the flocculo nodular lobe

18

Dentate Nucleus

Pons

PontineProjections

DentateNucleus

SuperiorCerebellarPeduncle

19

Somatotopic Organization

Tactile informationndash Ipsilateral anterior lobule ndash Bilateral paramedian lobulesndash Cerebral Cortex and

Cerebellum have similar representations

Motor representationndash Same area as sensory

mappingndash May have auditory and visual

processing

20

Afferent Pathways (Inferior)

Vestibulocerebellar Tractndash Info From Semicircular Canals Through Inferior

Pedunclendash Maintains Upright Posture

Dorsal Spinocerebellar Tractndash Info From Reticular Nuclei (involved in regulation

of sleep respiration heartbeat etc)ndash Unconscious Proprioception From Muscle

Spindles Golgi Tendons and Tactile Receptors

21

Afferent and Efferent Projections

Superior CerebellarPeduncle

Red nucleus

Thalamus

Middle CerebellarPeduncle (pontocerebellar fibers)

Inferior Cerebellar Nucleus(olivocerebellar fibers)

22

Afferent Pathways (Middle)

Info From Pontine Nuclei From Opposite Cerebral Cortex Visual and Auditory Inputs

To Opposite Cerebellar Hemisphere

Afferent Connections amp Functions

23

Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve

Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in

located posteriorly in the superior vermis

Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate

24

Efferent Pathways

Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex

Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium

25

Cerebellar Cortex

Structured in Three Parallel Layersndash Molecularndash Purkinje

Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex

ndash GranularHave Mossy Fiber Axons to Purkinje Axons

CELL TYPES AND CIRCUITS IN THE CEREBELLUM

Cerebellar Cortex

Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell

Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely

branched dendrites (400 000 synapses)

Granular cells- vast numbers of small neurons with axons ascending into the molecular layer

27

PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES

TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS

OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS

CEREBELLAR LESIONS

IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN

COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE

ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS

PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA

30

Clinical Considerations

Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia

Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)

ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody

Overview of Hypothalamus

Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures

31

Functions of Hypothalamus

Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious

ndash Temperature regulationndash Feeding

32

33

Regulates Mechanism by

Receiving sensory information from all areas of the body

Comparing sensory information with biological set points

Adjusting the system to restore the body balance when deviations from biological set points occur

Example Set pointsndash Blood sugar Hormone levels Temperature

Sodium34

Autonomic nervous system regulationInfluences PSNS through projections to brainstem

PSNS nuclei

Posterior area influences SNS through projections to the lateral gray horn

35

Hormone ProductionMagnocellular regions of the supraoptic and

paraventricular nuclei produce oxytocin and vassopressin (ADH)

Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700

Released in circulationDamage to supraoptic n diabetes insipidusrArr

36

Hormone Production

ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis

37

Cercadian rhythm regulation

ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland

38

Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills

Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating

39

13

Transverse Cerebellar Regions

1 Floccular nodular lobe (Archicerebellum )ndash Oldest related to vestibular part of VIIIndash Regulates equilibrium through vestibulospinal tract

2 Anterior lobe (Paleocerebellum)ndash Rostral to Primary Fissurendash General Sensory Receptorsndash Concerned with muscle tone and walking

3 Posterior lobe (Neocerebellum)ndash Newest and Largest Receives afferent projections from contralateral

sensorimotor cortexndash Projects to contralateral motor cortexndash Functions in coordination of fine and skilled movements

14

Longitudinal Cerebellar Regions

Vermisndash Contributes to body posture

Paravermal regionndash Regulates movements of ipsilateral extremities

(eg walking)

Lateral Zonendash Regulates skilled movements of ipsilateral

extremity (eg tying your shoe)

15

Cerebellar Connection

Three Peduncles1 Inferior ndash afferent mediate sensorimotor input to the

cerebellum2 Middle ndash afferent same as above3 Superior ndash efferent transmit output from the cerebellum to

the brainstem and on to the thalamus motor cortex and spinal cord

Varied afferents to Cerebellum ndash spinal cordndash brainstem ndash motor cortex

AfferenetEfferent Ratio = 401ndash For each going from cerebellum to body 40 coming in

Cerebellar Nuclei

16

Dentate NucleusNeocerebellum

Paleocerebellum Globose amp emboliform nuclei

Archecerebellum

Fastigeal Nucleus

Vestibular Nucleus

17

Cerebellar Nuclei (Nuclei = deep cluster of neurons)

Dentate nucleusndash Largest communicates through cerebellar peduncle ndash Carries information important for coordination of limb

movements (along with the motor cortex and basal ganglia)

Emboliform nucleus (medial side of the nucleus dentatus)ndash Regulates movements of ipsilateral extremity

Globose nucleusndash Regulates movements of ipsilateral extremity

Fastigial nucleusndash Regulates body posturendash Is related to the flocculo nodular lobe

18

Dentate Nucleus

Pons

PontineProjections

DentateNucleus

SuperiorCerebellarPeduncle

19

Somatotopic Organization

Tactile informationndash Ipsilateral anterior lobule ndash Bilateral paramedian lobulesndash Cerebral Cortex and

Cerebellum have similar representations

Motor representationndash Same area as sensory

mappingndash May have auditory and visual

processing

20

Afferent Pathways (Inferior)

Vestibulocerebellar Tractndash Info From Semicircular Canals Through Inferior

Pedunclendash Maintains Upright Posture

Dorsal Spinocerebellar Tractndash Info From Reticular Nuclei (involved in regulation

of sleep respiration heartbeat etc)ndash Unconscious Proprioception From Muscle

Spindles Golgi Tendons and Tactile Receptors

21

Afferent and Efferent Projections

Superior CerebellarPeduncle

Red nucleus

Thalamus

Middle CerebellarPeduncle (pontocerebellar fibers)

Inferior Cerebellar Nucleus(olivocerebellar fibers)

22

Afferent Pathways (Middle)

Info From Pontine Nuclei From Opposite Cerebral Cortex Visual and Auditory Inputs

To Opposite Cerebellar Hemisphere

Afferent Connections amp Functions

23

Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve

Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in

located posteriorly in the superior vermis

Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate

24

Efferent Pathways

Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex

Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium

25

Cerebellar Cortex

Structured in Three Parallel Layersndash Molecularndash Purkinje

Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex

ndash GranularHave Mossy Fiber Axons to Purkinje Axons

CELL TYPES AND CIRCUITS IN THE CEREBELLUM

Cerebellar Cortex

Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell

Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely

branched dendrites (400 000 synapses)

Granular cells- vast numbers of small neurons with axons ascending into the molecular layer

27

PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES

TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS

OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS

CEREBELLAR LESIONS

IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN

COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE

ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS

PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA

30

Clinical Considerations

Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia

Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)

ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody

Overview of Hypothalamus

Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures

31

Functions of Hypothalamus

Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious

ndash Temperature regulationndash Feeding

32

33

Regulates Mechanism by

Receiving sensory information from all areas of the body

Comparing sensory information with biological set points

Adjusting the system to restore the body balance when deviations from biological set points occur

Example Set pointsndash Blood sugar Hormone levels Temperature

Sodium34

Autonomic nervous system regulationInfluences PSNS through projections to brainstem

PSNS nuclei

Posterior area influences SNS through projections to the lateral gray horn

35

Hormone ProductionMagnocellular regions of the supraoptic and

paraventricular nuclei produce oxytocin and vassopressin (ADH)

Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700

Released in circulationDamage to supraoptic n diabetes insipidusrArr

36

Hormone Production

ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis

37

Cercadian rhythm regulation

ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland

38

Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills

Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating

39

14

Longitudinal Cerebellar Regions

Vermisndash Contributes to body posture

Paravermal regionndash Regulates movements of ipsilateral extremities

(eg walking)

Lateral Zonendash Regulates skilled movements of ipsilateral

extremity (eg tying your shoe)

15

Cerebellar Connection

Three Peduncles1 Inferior ndash afferent mediate sensorimotor input to the

cerebellum2 Middle ndash afferent same as above3 Superior ndash efferent transmit output from the cerebellum to

the brainstem and on to the thalamus motor cortex and spinal cord

Varied afferents to Cerebellum ndash spinal cordndash brainstem ndash motor cortex

AfferenetEfferent Ratio = 401ndash For each going from cerebellum to body 40 coming in

Cerebellar Nuclei

16

Dentate NucleusNeocerebellum

Paleocerebellum Globose amp emboliform nuclei

Archecerebellum

Fastigeal Nucleus

Vestibular Nucleus

17

Cerebellar Nuclei (Nuclei = deep cluster of neurons)

Dentate nucleusndash Largest communicates through cerebellar peduncle ndash Carries information important for coordination of limb

movements (along with the motor cortex and basal ganglia)

Emboliform nucleus (medial side of the nucleus dentatus)ndash Regulates movements of ipsilateral extremity

Globose nucleusndash Regulates movements of ipsilateral extremity

Fastigial nucleusndash Regulates body posturendash Is related to the flocculo nodular lobe

18

Dentate Nucleus

Pons

PontineProjections

DentateNucleus

SuperiorCerebellarPeduncle

19

Somatotopic Organization

Tactile informationndash Ipsilateral anterior lobule ndash Bilateral paramedian lobulesndash Cerebral Cortex and

Cerebellum have similar representations

Motor representationndash Same area as sensory

mappingndash May have auditory and visual

processing

20

Afferent Pathways (Inferior)

Vestibulocerebellar Tractndash Info From Semicircular Canals Through Inferior

Pedunclendash Maintains Upright Posture

Dorsal Spinocerebellar Tractndash Info From Reticular Nuclei (involved in regulation

of sleep respiration heartbeat etc)ndash Unconscious Proprioception From Muscle

Spindles Golgi Tendons and Tactile Receptors

21

Afferent and Efferent Projections

Superior CerebellarPeduncle

Red nucleus

Thalamus

Middle CerebellarPeduncle (pontocerebellar fibers)

Inferior Cerebellar Nucleus(olivocerebellar fibers)

22

Afferent Pathways (Middle)

Info From Pontine Nuclei From Opposite Cerebral Cortex Visual and Auditory Inputs

To Opposite Cerebellar Hemisphere

Afferent Connections amp Functions

23

Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve

Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in

located posteriorly in the superior vermis

Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate

24

Efferent Pathways

Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex

Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium

25

Cerebellar Cortex

Structured in Three Parallel Layersndash Molecularndash Purkinje

Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex

ndash GranularHave Mossy Fiber Axons to Purkinje Axons

CELL TYPES AND CIRCUITS IN THE CEREBELLUM

Cerebellar Cortex

Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell

Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely

branched dendrites (400 000 synapses)

Granular cells- vast numbers of small neurons with axons ascending into the molecular layer

27

PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES

TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS

OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS

CEREBELLAR LESIONS

IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN

COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE

ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS

PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA

30

Clinical Considerations

Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia

Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)

ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody

Overview of Hypothalamus

Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures

31

Functions of Hypothalamus

Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious

ndash Temperature regulationndash Feeding

32

33

Regulates Mechanism by

Receiving sensory information from all areas of the body

Comparing sensory information with biological set points

Adjusting the system to restore the body balance when deviations from biological set points occur

Example Set pointsndash Blood sugar Hormone levels Temperature

Sodium34

Autonomic nervous system regulationInfluences PSNS through projections to brainstem

PSNS nuclei

Posterior area influences SNS through projections to the lateral gray horn

35

Hormone ProductionMagnocellular regions of the supraoptic and

paraventricular nuclei produce oxytocin and vassopressin (ADH)

Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700

Released in circulationDamage to supraoptic n diabetes insipidusrArr

36

Hormone Production

ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis

37

Cercadian rhythm regulation

ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland

38

Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills

Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating

39

15

Cerebellar Connection

Three Peduncles1 Inferior ndash afferent mediate sensorimotor input to the

cerebellum2 Middle ndash afferent same as above3 Superior ndash efferent transmit output from the cerebellum to

the brainstem and on to the thalamus motor cortex and spinal cord

Varied afferents to Cerebellum ndash spinal cordndash brainstem ndash motor cortex

AfferenetEfferent Ratio = 401ndash For each going from cerebellum to body 40 coming in

Cerebellar Nuclei

16

Dentate NucleusNeocerebellum

Paleocerebellum Globose amp emboliform nuclei

Archecerebellum

Fastigeal Nucleus

Vestibular Nucleus

17

Cerebellar Nuclei (Nuclei = deep cluster of neurons)

Dentate nucleusndash Largest communicates through cerebellar peduncle ndash Carries information important for coordination of limb

movements (along with the motor cortex and basal ganglia)

Emboliform nucleus (medial side of the nucleus dentatus)ndash Regulates movements of ipsilateral extremity

Globose nucleusndash Regulates movements of ipsilateral extremity

Fastigial nucleusndash Regulates body posturendash Is related to the flocculo nodular lobe

18

Dentate Nucleus

Pons

PontineProjections

DentateNucleus

SuperiorCerebellarPeduncle

19

Somatotopic Organization

Tactile informationndash Ipsilateral anterior lobule ndash Bilateral paramedian lobulesndash Cerebral Cortex and

Cerebellum have similar representations

Motor representationndash Same area as sensory

mappingndash May have auditory and visual

processing

20

Afferent Pathways (Inferior)

Vestibulocerebellar Tractndash Info From Semicircular Canals Through Inferior

Pedunclendash Maintains Upright Posture

Dorsal Spinocerebellar Tractndash Info From Reticular Nuclei (involved in regulation

of sleep respiration heartbeat etc)ndash Unconscious Proprioception From Muscle

Spindles Golgi Tendons and Tactile Receptors

21

Afferent and Efferent Projections

Superior CerebellarPeduncle

Red nucleus

Thalamus

Middle CerebellarPeduncle (pontocerebellar fibers)

Inferior Cerebellar Nucleus(olivocerebellar fibers)

22

Afferent Pathways (Middle)

Info From Pontine Nuclei From Opposite Cerebral Cortex Visual and Auditory Inputs

To Opposite Cerebellar Hemisphere

Afferent Connections amp Functions

23

Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve

Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in

located posteriorly in the superior vermis

Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate

24

Efferent Pathways

Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex

Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium

25

Cerebellar Cortex

Structured in Three Parallel Layersndash Molecularndash Purkinje

Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex

ndash GranularHave Mossy Fiber Axons to Purkinje Axons

CELL TYPES AND CIRCUITS IN THE CEREBELLUM

Cerebellar Cortex

Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell

Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely

branched dendrites (400 000 synapses)

Granular cells- vast numbers of small neurons with axons ascending into the molecular layer

27

PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES

TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS

OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS

CEREBELLAR LESIONS

IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN

COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE

ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS

PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA

30

Clinical Considerations

Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia

Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)

ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody

Overview of Hypothalamus

Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures

31

Functions of Hypothalamus

Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious

ndash Temperature regulationndash Feeding

32

33

Regulates Mechanism by

Receiving sensory information from all areas of the body

Comparing sensory information with biological set points

Adjusting the system to restore the body balance when deviations from biological set points occur

Example Set pointsndash Blood sugar Hormone levels Temperature

Sodium34

Autonomic nervous system regulationInfluences PSNS through projections to brainstem

PSNS nuclei

Posterior area influences SNS through projections to the lateral gray horn

35

Hormone ProductionMagnocellular regions of the supraoptic and

paraventricular nuclei produce oxytocin and vassopressin (ADH)

Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700

Released in circulationDamage to supraoptic n diabetes insipidusrArr

36

Hormone Production

ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis

37

Cercadian rhythm regulation

ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland

38

Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills

Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating

39

Cerebellar Nuclei

16

Dentate NucleusNeocerebellum

Paleocerebellum Globose amp emboliform nuclei

Archecerebellum

Fastigeal Nucleus

Vestibular Nucleus

17

Cerebellar Nuclei (Nuclei = deep cluster of neurons)

Dentate nucleusndash Largest communicates through cerebellar peduncle ndash Carries information important for coordination of limb

movements (along with the motor cortex and basal ganglia)

Emboliform nucleus (medial side of the nucleus dentatus)ndash Regulates movements of ipsilateral extremity

Globose nucleusndash Regulates movements of ipsilateral extremity

Fastigial nucleusndash Regulates body posturendash Is related to the flocculo nodular lobe

18

Dentate Nucleus

Pons

PontineProjections

DentateNucleus

SuperiorCerebellarPeduncle

19

Somatotopic Organization

Tactile informationndash Ipsilateral anterior lobule ndash Bilateral paramedian lobulesndash Cerebral Cortex and

Cerebellum have similar representations

Motor representationndash Same area as sensory

mappingndash May have auditory and visual

processing

20

Afferent Pathways (Inferior)

Vestibulocerebellar Tractndash Info From Semicircular Canals Through Inferior

Pedunclendash Maintains Upright Posture

Dorsal Spinocerebellar Tractndash Info From Reticular Nuclei (involved in regulation

of sleep respiration heartbeat etc)ndash Unconscious Proprioception From Muscle

Spindles Golgi Tendons and Tactile Receptors

21

Afferent and Efferent Projections

Superior CerebellarPeduncle

Red nucleus

Thalamus

Middle CerebellarPeduncle (pontocerebellar fibers)

Inferior Cerebellar Nucleus(olivocerebellar fibers)

22

Afferent Pathways (Middle)

Info From Pontine Nuclei From Opposite Cerebral Cortex Visual and Auditory Inputs

To Opposite Cerebellar Hemisphere

Afferent Connections amp Functions

23

Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve

Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in

located posteriorly in the superior vermis

Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate

24

Efferent Pathways

Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex

Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium

25

Cerebellar Cortex

Structured in Three Parallel Layersndash Molecularndash Purkinje

Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex

ndash GranularHave Mossy Fiber Axons to Purkinje Axons

CELL TYPES AND CIRCUITS IN THE CEREBELLUM

Cerebellar Cortex

Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell

Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely

branched dendrites (400 000 synapses)

Granular cells- vast numbers of small neurons with axons ascending into the molecular layer

27

PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES

TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS

OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS

CEREBELLAR LESIONS

IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN

COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE

ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS

PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA

30

Clinical Considerations

Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia

Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)

ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody

Overview of Hypothalamus

Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures

31

Functions of Hypothalamus

Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious

ndash Temperature regulationndash Feeding

32

33

Regulates Mechanism by

Receiving sensory information from all areas of the body

Comparing sensory information with biological set points

Adjusting the system to restore the body balance when deviations from biological set points occur

Example Set pointsndash Blood sugar Hormone levels Temperature

Sodium34

Autonomic nervous system regulationInfluences PSNS through projections to brainstem

PSNS nuclei

Posterior area influences SNS through projections to the lateral gray horn

35

Hormone ProductionMagnocellular regions of the supraoptic and

paraventricular nuclei produce oxytocin and vassopressin (ADH)

Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700

Released in circulationDamage to supraoptic n diabetes insipidusrArr

36

Hormone Production

ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis

37

Cercadian rhythm regulation

ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland

38

Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills

Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating

39

17

Cerebellar Nuclei (Nuclei = deep cluster of neurons)

Dentate nucleusndash Largest communicates through cerebellar peduncle ndash Carries information important for coordination of limb

movements (along with the motor cortex and basal ganglia)

Emboliform nucleus (medial side of the nucleus dentatus)ndash Regulates movements of ipsilateral extremity

Globose nucleusndash Regulates movements of ipsilateral extremity

Fastigial nucleusndash Regulates body posturendash Is related to the flocculo nodular lobe

18

Dentate Nucleus

Pons

PontineProjections

DentateNucleus

SuperiorCerebellarPeduncle

19

Somatotopic Organization

Tactile informationndash Ipsilateral anterior lobule ndash Bilateral paramedian lobulesndash Cerebral Cortex and

Cerebellum have similar representations

Motor representationndash Same area as sensory

mappingndash May have auditory and visual

processing

20

Afferent Pathways (Inferior)

Vestibulocerebellar Tractndash Info From Semicircular Canals Through Inferior

Pedunclendash Maintains Upright Posture

Dorsal Spinocerebellar Tractndash Info From Reticular Nuclei (involved in regulation

of sleep respiration heartbeat etc)ndash Unconscious Proprioception From Muscle

Spindles Golgi Tendons and Tactile Receptors

21

Afferent and Efferent Projections

Superior CerebellarPeduncle

Red nucleus

Thalamus

Middle CerebellarPeduncle (pontocerebellar fibers)

Inferior Cerebellar Nucleus(olivocerebellar fibers)

22

Afferent Pathways (Middle)

Info From Pontine Nuclei From Opposite Cerebral Cortex Visual and Auditory Inputs

To Opposite Cerebellar Hemisphere

Afferent Connections amp Functions

23

Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve

Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in

located posteriorly in the superior vermis

Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate

24

Efferent Pathways

Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex

Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium

25

Cerebellar Cortex

Structured in Three Parallel Layersndash Molecularndash Purkinje

Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex

ndash GranularHave Mossy Fiber Axons to Purkinje Axons

CELL TYPES AND CIRCUITS IN THE CEREBELLUM

Cerebellar Cortex

Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell

Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely

branched dendrites (400 000 synapses)

Granular cells- vast numbers of small neurons with axons ascending into the molecular layer

27

PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES

TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS

OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS

CEREBELLAR LESIONS

IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN

COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE

ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS

PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA

30

Clinical Considerations

Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia

Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)

ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody

Overview of Hypothalamus

Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures

31

Functions of Hypothalamus

Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious

ndash Temperature regulationndash Feeding

32

33

Regulates Mechanism by

Receiving sensory information from all areas of the body

Comparing sensory information with biological set points

Adjusting the system to restore the body balance when deviations from biological set points occur

Example Set pointsndash Blood sugar Hormone levels Temperature

Sodium34

Autonomic nervous system regulationInfluences PSNS through projections to brainstem

PSNS nuclei

Posterior area influences SNS through projections to the lateral gray horn

35

Hormone ProductionMagnocellular regions of the supraoptic and

paraventricular nuclei produce oxytocin and vassopressin (ADH)

Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700

Released in circulationDamage to supraoptic n diabetes insipidusrArr

36

Hormone Production

ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis

37

Cercadian rhythm regulation

ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland

38

Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills

Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating

39

18

Dentate Nucleus

Pons

PontineProjections

DentateNucleus

SuperiorCerebellarPeduncle

19

Somatotopic Organization

Tactile informationndash Ipsilateral anterior lobule ndash Bilateral paramedian lobulesndash Cerebral Cortex and

Cerebellum have similar representations

Motor representationndash Same area as sensory

mappingndash May have auditory and visual

processing

20

Afferent Pathways (Inferior)

Vestibulocerebellar Tractndash Info From Semicircular Canals Through Inferior

Pedunclendash Maintains Upright Posture

Dorsal Spinocerebellar Tractndash Info From Reticular Nuclei (involved in regulation

of sleep respiration heartbeat etc)ndash Unconscious Proprioception From Muscle

Spindles Golgi Tendons and Tactile Receptors

21

Afferent and Efferent Projections

Superior CerebellarPeduncle

Red nucleus

Thalamus

Middle CerebellarPeduncle (pontocerebellar fibers)

Inferior Cerebellar Nucleus(olivocerebellar fibers)

22

Afferent Pathways (Middle)

Info From Pontine Nuclei From Opposite Cerebral Cortex Visual and Auditory Inputs

To Opposite Cerebellar Hemisphere

Afferent Connections amp Functions

23

Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve

Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in

located posteriorly in the superior vermis

Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate

24

Efferent Pathways

Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex

Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium

25

Cerebellar Cortex

Structured in Three Parallel Layersndash Molecularndash Purkinje

Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex

ndash GranularHave Mossy Fiber Axons to Purkinje Axons

CELL TYPES AND CIRCUITS IN THE CEREBELLUM

Cerebellar Cortex

Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell

Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely

branched dendrites (400 000 synapses)

Granular cells- vast numbers of small neurons with axons ascending into the molecular layer

27

PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES

TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS

OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS

CEREBELLAR LESIONS

IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN

COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE

ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS

PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA

30

Clinical Considerations

Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia

Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)

ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody

Overview of Hypothalamus

Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures

31

Functions of Hypothalamus

Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious

ndash Temperature regulationndash Feeding

32

33

Regulates Mechanism by

Receiving sensory information from all areas of the body

Comparing sensory information with biological set points

Adjusting the system to restore the body balance when deviations from biological set points occur

Example Set pointsndash Blood sugar Hormone levels Temperature

Sodium34

Autonomic nervous system regulationInfluences PSNS through projections to brainstem

PSNS nuclei

Posterior area influences SNS through projections to the lateral gray horn

35

Hormone ProductionMagnocellular regions of the supraoptic and

paraventricular nuclei produce oxytocin and vassopressin (ADH)

Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700

Released in circulationDamage to supraoptic n diabetes insipidusrArr

36

Hormone Production

ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis

37

Cercadian rhythm regulation

ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland

38

Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills

Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating

39

19

Somatotopic Organization

Tactile informationndash Ipsilateral anterior lobule ndash Bilateral paramedian lobulesndash Cerebral Cortex and

Cerebellum have similar representations

Motor representationndash Same area as sensory

mappingndash May have auditory and visual

processing

20

Afferent Pathways (Inferior)

Vestibulocerebellar Tractndash Info From Semicircular Canals Through Inferior

Pedunclendash Maintains Upright Posture

Dorsal Spinocerebellar Tractndash Info From Reticular Nuclei (involved in regulation

of sleep respiration heartbeat etc)ndash Unconscious Proprioception From Muscle

Spindles Golgi Tendons and Tactile Receptors

21

Afferent and Efferent Projections

Superior CerebellarPeduncle

Red nucleus

Thalamus

Middle CerebellarPeduncle (pontocerebellar fibers)

Inferior Cerebellar Nucleus(olivocerebellar fibers)

22

Afferent Pathways (Middle)

Info From Pontine Nuclei From Opposite Cerebral Cortex Visual and Auditory Inputs

To Opposite Cerebellar Hemisphere

Afferent Connections amp Functions

23

Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve

Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in

located posteriorly in the superior vermis

Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate

24

Efferent Pathways

Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex

Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium

25

Cerebellar Cortex

Structured in Three Parallel Layersndash Molecularndash Purkinje

Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex

ndash GranularHave Mossy Fiber Axons to Purkinje Axons

CELL TYPES AND CIRCUITS IN THE CEREBELLUM

Cerebellar Cortex

Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell

Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely

branched dendrites (400 000 synapses)

Granular cells- vast numbers of small neurons with axons ascending into the molecular layer

27

PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES

TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS

OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS

CEREBELLAR LESIONS

IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN

COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE

ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS

PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA

30

Clinical Considerations

Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia

Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)

ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody

Overview of Hypothalamus

Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures

31

Functions of Hypothalamus

Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious

ndash Temperature regulationndash Feeding

32

33

Regulates Mechanism by

Receiving sensory information from all areas of the body

Comparing sensory information with biological set points

Adjusting the system to restore the body balance when deviations from biological set points occur

Example Set pointsndash Blood sugar Hormone levels Temperature

Sodium34

Autonomic nervous system regulationInfluences PSNS through projections to brainstem

PSNS nuclei

Posterior area influences SNS through projections to the lateral gray horn

35

Hormone ProductionMagnocellular regions of the supraoptic and

paraventricular nuclei produce oxytocin and vassopressin (ADH)

Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700

Released in circulationDamage to supraoptic n diabetes insipidusrArr

36

Hormone Production

ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis

37

Cercadian rhythm regulation

ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland

38

Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills

Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating

39

20

Afferent Pathways (Inferior)

Vestibulocerebellar Tractndash Info From Semicircular Canals Through Inferior

Pedunclendash Maintains Upright Posture

Dorsal Spinocerebellar Tractndash Info From Reticular Nuclei (involved in regulation

of sleep respiration heartbeat etc)ndash Unconscious Proprioception From Muscle

Spindles Golgi Tendons and Tactile Receptors

21

Afferent and Efferent Projections

Superior CerebellarPeduncle

Red nucleus

Thalamus

Middle CerebellarPeduncle (pontocerebellar fibers)

Inferior Cerebellar Nucleus(olivocerebellar fibers)

22

Afferent Pathways (Middle)

Info From Pontine Nuclei From Opposite Cerebral Cortex Visual and Auditory Inputs

To Opposite Cerebellar Hemisphere

Afferent Connections amp Functions

23

Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve

Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in

located posteriorly in the superior vermis

Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate

24

Efferent Pathways

Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex

Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium

25

Cerebellar Cortex

Structured in Three Parallel Layersndash Molecularndash Purkinje

Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex

ndash GranularHave Mossy Fiber Axons to Purkinje Axons

CELL TYPES AND CIRCUITS IN THE CEREBELLUM

Cerebellar Cortex

Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell

Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely

branched dendrites (400 000 synapses)

Granular cells- vast numbers of small neurons with axons ascending into the molecular layer

27

PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES

TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS

OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS

CEREBELLAR LESIONS

IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN

COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE

ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS

PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA

30

Clinical Considerations

Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia

Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)

ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody

Overview of Hypothalamus

Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures

31

Functions of Hypothalamus

Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious

ndash Temperature regulationndash Feeding

32

33

Regulates Mechanism by

Receiving sensory information from all areas of the body

Comparing sensory information with biological set points

Adjusting the system to restore the body balance when deviations from biological set points occur

Example Set pointsndash Blood sugar Hormone levels Temperature

Sodium34

Autonomic nervous system regulationInfluences PSNS through projections to brainstem

PSNS nuclei

Posterior area influences SNS through projections to the lateral gray horn

35

Hormone ProductionMagnocellular regions of the supraoptic and

paraventricular nuclei produce oxytocin and vassopressin (ADH)

Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700

Released in circulationDamage to supraoptic n diabetes insipidusrArr

36

Hormone Production

ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis

37

Cercadian rhythm regulation

ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland

38

Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills

Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating

39

21

Afferent and Efferent Projections

Superior CerebellarPeduncle

Red nucleus

Thalamus

Middle CerebellarPeduncle (pontocerebellar fibers)

Inferior Cerebellar Nucleus(olivocerebellar fibers)

22

Afferent Pathways (Middle)

Info From Pontine Nuclei From Opposite Cerebral Cortex Visual and Auditory Inputs

To Opposite Cerebellar Hemisphere

Afferent Connections amp Functions

23

Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve

Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in

located posteriorly in the superior vermis

Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate

24

Efferent Pathways

Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex

Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium

25

Cerebellar Cortex

Structured in Three Parallel Layersndash Molecularndash Purkinje

Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex

ndash GranularHave Mossy Fiber Axons to Purkinje Axons

CELL TYPES AND CIRCUITS IN THE CEREBELLUM

Cerebellar Cortex

Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell

Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely

branched dendrites (400 000 synapses)

Granular cells- vast numbers of small neurons with axons ascending into the molecular layer

27

PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES

TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS

OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS

CEREBELLAR LESIONS

IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN

COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE

ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS

PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA

30

Clinical Considerations

Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia

Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)

ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody

Overview of Hypothalamus

Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures

31

Functions of Hypothalamus

Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious

ndash Temperature regulationndash Feeding

32

33

Regulates Mechanism by

Receiving sensory information from all areas of the body

Comparing sensory information with biological set points

Adjusting the system to restore the body balance when deviations from biological set points occur

Example Set pointsndash Blood sugar Hormone levels Temperature

Sodium34

Autonomic nervous system regulationInfluences PSNS through projections to brainstem

PSNS nuclei

Posterior area influences SNS through projections to the lateral gray horn

35

Hormone ProductionMagnocellular regions of the supraoptic and

paraventricular nuclei produce oxytocin and vassopressin (ADH)

Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700

Released in circulationDamage to supraoptic n diabetes insipidusrArr

36

Hormone Production

ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis

37

Cercadian rhythm regulation

ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland

38

Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills

Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating

39

22

Afferent Pathways (Middle)

Info From Pontine Nuclei From Opposite Cerebral Cortex Visual and Auditory Inputs

To Opposite Cerebellar Hemisphere

Afferent Connections amp Functions

23

Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve

Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in

located posteriorly in the superior vermis

Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate

24

Efferent Pathways

Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex

Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium

25

Cerebellar Cortex

Structured in Three Parallel Layersndash Molecularndash Purkinje

Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex

ndash GranularHave Mossy Fiber Axons to Purkinje Axons

CELL TYPES AND CIRCUITS IN THE CEREBELLUM

Cerebellar Cortex

Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell

Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely

branched dendrites (400 000 synapses)

Granular cells- vast numbers of small neurons with axons ascending into the molecular layer

27

PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES

TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS

OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS

CEREBELLAR LESIONS

IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN

COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE

ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS

PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA

30

Clinical Considerations

Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia

Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)

ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody

Overview of Hypothalamus

Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures

31

Functions of Hypothalamus

Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious

ndash Temperature regulationndash Feeding

32

33

Regulates Mechanism by

Receiving sensory information from all areas of the body

Comparing sensory information with biological set points

Adjusting the system to restore the body balance when deviations from biological set points occur

Example Set pointsndash Blood sugar Hormone levels Temperature

Sodium34

Autonomic nervous system regulationInfluences PSNS through projections to brainstem

PSNS nuclei

Posterior area influences SNS through projections to the lateral gray horn

35

Hormone ProductionMagnocellular regions of the supraoptic and

paraventricular nuclei produce oxytocin and vassopressin (ADH)

Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700

Released in circulationDamage to supraoptic n diabetes insipidusrArr

36

Hormone Production

ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis

37

Cercadian rhythm regulation

ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland

38

Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills

Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating

39

Afferent Connections amp Functions

23

Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve

Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in

located posteriorly in the superior vermis

Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate

24

Efferent Pathways

Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex

Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium

25

Cerebellar Cortex

Structured in Three Parallel Layersndash Molecularndash Purkinje

Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex

ndash GranularHave Mossy Fiber Axons to Purkinje Axons

CELL TYPES AND CIRCUITS IN THE CEREBELLUM

Cerebellar Cortex

Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell

Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely

branched dendrites (400 000 synapses)

Granular cells- vast numbers of small neurons with axons ascending into the molecular layer

27

PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES

TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS

OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS

CEREBELLAR LESIONS

IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN

COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE

ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS

PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA

30

Clinical Considerations

Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia

Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)

ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody

Overview of Hypothalamus

Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures

31

Functions of Hypothalamus

Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious

ndash Temperature regulationndash Feeding

32

33

Regulates Mechanism by

Receiving sensory information from all areas of the body

Comparing sensory information with biological set points

Adjusting the system to restore the body balance when deviations from biological set points occur

Example Set pointsndash Blood sugar Hormone levels Temperature

Sodium34

Autonomic nervous system regulationInfluences PSNS through projections to brainstem

PSNS nuclei

Posterior area influences SNS through projections to the lateral gray horn

35

Hormone ProductionMagnocellular regions of the supraoptic and

paraventricular nuclei produce oxytocin and vassopressin (ADH)

Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700

Released in circulationDamage to supraoptic n diabetes insipidusrArr

36

Hormone Production

ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis

37

Cercadian rhythm regulation

ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland

38

Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills

Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating

39

24

Efferent Pathways

Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex

Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium

25

Cerebellar Cortex

Structured in Three Parallel Layersndash Molecularndash Purkinje

Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex

ndash GranularHave Mossy Fiber Axons to Purkinje Axons

CELL TYPES AND CIRCUITS IN THE CEREBELLUM

Cerebellar Cortex

Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell

Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely

branched dendrites (400 000 synapses)

Granular cells- vast numbers of small neurons with axons ascending into the molecular layer

27

PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES

TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS

OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS

CEREBELLAR LESIONS

IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN

COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE

ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS

PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA

30

Clinical Considerations

Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia

Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)

ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody

Overview of Hypothalamus

Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures

31

Functions of Hypothalamus

Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious

ndash Temperature regulationndash Feeding

32

33

Regulates Mechanism by

Receiving sensory information from all areas of the body

Comparing sensory information with biological set points

Adjusting the system to restore the body balance when deviations from biological set points occur

Example Set pointsndash Blood sugar Hormone levels Temperature

Sodium34

Autonomic nervous system regulationInfluences PSNS through projections to brainstem

PSNS nuclei

Posterior area influences SNS through projections to the lateral gray horn

35

Hormone ProductionMagnocellular regions of the supraoptic and

paraventricular nuclei produce oxytocin and vassopressin (ADH)

Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700

Released in circulationDamage to supraoptic n diabetes insipidusrArr

36

Hormone Production

ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis

37

Cercadian rhythm regulation

ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland

38

Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills

Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating

39

25

Cerebellar Cortex

Structured in Three Parallel Layersndash Molecularndash Purkinje

Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex

ndash GranularHave Mossy Fiber Axons to Purkinje Axons

CELL TYPES AND CIRCUITS IN THE CEREBELLUM

Cerebellar Cortex

Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell

Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely

branched dendrites (400 000 synapses)

Granular cells- vast numbers of small neurons with axons ascending into the molecular layer

27

PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES

TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS

OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS

CEREBELLAR LESIONS

IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN

COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE

ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS

PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA

30

Clinical Considerations

Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia

Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)

ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody

Overview of Hypothalamus

Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures

31

Functions of Hypothalamus

Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious

ndash Temperature regulationndash Feeding

32

33

Regulates Mechanism by

Receiving sensory information from all areas of the body

Comparing sensory information with biological set points

Adjusting the system to restore the body balance when deviations from biological set points occur

Example Set pointsndash Blood sugar Hormone levels Temperature

Sodium34

Autonomic nervous system regulationInfluences PSNS through projections to brainstem

PSNS nuclei

Posterior area influences SNS through projections to the lateral gray horn

35

Hormone ProductionMagnocellular regions of the supraoptic and

paraventricular nuclei produce oxytocin and vassopressin (ADH)

Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700

Released in circulationDamage to supraoptic n diabetes insipidusrArr

36

Hormone Production

ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis

37

Cercadian rhythm regulation

ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland

38

Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills

Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating

39

CELL TYPES AND CIRCUITS IN THE CEREBELLUM

Cerebellar Cortex

Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell

Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely

branched dendrites (400 000 synapses)

Granular cells- vast numbers of small neurons with axons ascending into the molecular layer

27

PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES

TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS

OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS

CEREBELLAR LESIONS

IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN

COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE

ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS

PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA

30

Clinical Considerations

Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia

Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)

ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody

Overview of Hypothalamus

Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures

31

Functions of Hypothalamus

Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious

ndash Temperature regulationndash Feeding

32

33

Regulates Mechanism by

Receiving sensory information from all areas of the body

Comparing sensory information with biological set points

Adjusting the system to restore the body balance when deviations from biological set points occur

Example Set pointsndash Blood sugar Hormone levels Temperature

Sodium34

Autonomic nervous system regulationInfluences PSNS through projections to brainstem

PSNS nuclei

Posterior area influences SNS through projections to the lateral gray horn

35

Hormone ProductionMagnocellular regions of the supraoptic and

paraventricular nuclei produce oxytocin and vassopressin (ADH)

Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700

Released in circulationDamage to supraoptic n diabetes insipidusrArr

36

Hormone Production

ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis

37

Cercadian rhythm regulation

ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland

38

Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills

Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating

39

Cerebellar Cortex

Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell

Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely

branched dendrites (400 000 synapses)

Granular cells- vast numbers of small neurons with axons ascending into the molecular layer

27

PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES

TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS

OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS

CEREBELLAR LESIONS

IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN

COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE

ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS

PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA

30

Clinical Considerations

Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia

Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)

ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody

Overview of Hypothalamus

Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures

31

Functions of Hypothalamus

Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious

ndash Temperature regulationndash Feeding

32

33

Regulates Mechanism by

Receiving sensory information from all areas of the body

Comparing sensory information with biological set points

Adjusting the system to restore the body balance when deviations from biological set points occur

Example Set pointsndash Blood sugar Hormone levels Temperature

Sodium34

Autonomic nervous system regulationInfluences PSNS through projections to brainstem

PSNS nuclei

Posterior area influences SNS through projections to the lateral gray horn

35

Hormone ProductionMagnocellular regions of the supraoptic and

paraventricular nuclei produce oxytocin and vassopressin (ADH)

Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700

Released in circulationDamage to supraoptic n diabetes insipidusrArr

36

Hormone Production

ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis

37

Cercadian rhythm regulation

ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland

38

Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills

Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating

39

PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES

TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS

OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS

CEREBELLAR LESIONS

IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN

COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE

ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS

PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA

30

Clinical Considerations

Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia

Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)

ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody

Overview of Hypothalamus

Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures

31

Functions of Hypothalamus

Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious

ndash Temperature regulationndash Feeding

32

33

Regulates Mechanism by

Receiving sensory information from all areas of the body

Comparing sensory information with biological set points

Adjusting the system to restore the body balance when deviations from biological set points occur

Example Set pointsndash Blood sugar Hormone levels Temperature

Sodium34

Autonomic nervous system regulationInfluences PSNS through projections to brainstem

PSNS nuclei

Posterior area influences SNS through projections to the lateral gray horn

35

Hormone ProductionMagnocellular regions of the supraoptic and

paraventricular nuclei produce oxytocin and vassopressin (ADH)

Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700

Released in circulationDamage to supraoptic n diabetes insipidusrArr

36

Hormone Production

ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis

37

Cercadian rhythm regulation

ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland

38

Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills

Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating

39

CEREBELLAR LESIONS

IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN

COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE

ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS

PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA

30

Clinical Considerations

Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia

Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)

ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody

Overview of Hypothalamus

Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures

31

Functions of Hypothalamus

Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious

ndash Temperature regulationndash Feeding

32

33

Regulates Mechanism by

Receiving sensory information from all areas of the body

Comparing sensory information with biological set points

Adjusting the system to restore the body balance when deviations from biological set points occur

Example Set pointsndash Blood sugar Hormone levels Temperature

Sodium34

Autonomic nervous system regulationInfluences PSNS through projections to brainstem

PSNS nuclei

Posterior area influences SNS through projections to the lateral gray horn

35

Hormone ProductionMagnocellular regions of the supraoptic and

paraventricular nuclei produce oxytocin and vassopressin (ADH)

Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700

Released in circulationDamage to supraoptic n diabetes insipidusrArr

36

Hormone Production

ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis

37

Cercadian rhythm regulation

ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland

38

Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills

Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating

39

30

Clinical Considerations

Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia

Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)

ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody

Overview of Hypothalamus

Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures

31

Functions of Hypothalamus

Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious

ndash Temperature regulationndash Feeding

32

33

Regulates Mechanism by

Receiving sensory information from all areas of the body

Comparing sensory information with biological set points

Adjusting the system to restore the body balance when deviations from biological set points occur

Example Set pointsndash Blood sugar Hormone levels Temperature

Sodium34

Autonomic nervous system regulationInfluences PSNS through projections to brainstem

PSNS nuclei

Posterior area influences SNS through projections to the lateral gray horn

35

Hormone ProductionMagnocellular regions of the supraoptic and

paraventricular nuclei produce oxytocin and vassopressin (ADH)

Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700

Released in circulationDamage to supraoptic n diabetes insipidusrArr

36

Hormone Production

ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis

37

Cercadian rhythm regulation

ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland

38

Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills

Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating

39

Overview of Hypothalamus

Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures

31

Functions of Hypothalamus

Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious

ndash Temperature regulationndash Feeding

32

33

Regulates Mechanism by

Receiving sensory information from all areas of the body

Comparing sensory information with biological set points

Adjusting the system to restore the body balance when deviations from biological set points occur

Example Set pointsndash Blood sugar Hormone levels Temperature

Sodium34

Autonomic nervous system regulationInfluences PSNS through projections to brainstem

PSNS nuclei

Posterior area influences SNS through projections to the lateral gray horn

35

Hormone ProductionMagnocellular regions of the supraoptic and

paraventricular nuclei produce oxytocin and vassopressin (ADH)

Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700

Released in circulationDamage to supraoptic n diabetes insipidusrArr

36

Hormone Production

ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis

37

Cercadian rhythm regulation

ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland

38

Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills

Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating

39

Functions of Hypothalamus

Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious

ndash Temperature regulationndash Feeding

32

33

Regulates Mechanism by

Receiving sensory information from all areas of the body

Comparing sensory information with biological set points

Adjusting the system to restore the body balance when deviations from biological set points occur

Example Set pointsndash Blood sugar Hormone levels Temperature

Sodium34

Autonomic nervous system regulationInfluences PSNS through projections to brainstem

PSNS nuclei

Posterior area influences SNS through projections to the lateral gray horn

35

Hormone ProductionMagnocellular regions of the supraoptic and

paraventricular nuclei produce oxytocin and vassopressin (ADH)

Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700

Released in circulationDamage to supraoptic n diabetes insipidusrArr

36

Hormone Production

ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis

37

Cercadian rhythm regulation

ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland

38

Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills

Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating

39

33

Regulates Mechanism by

Receiving sensory information from all areas of the body

Comparing sensory information with biological set points

Adjusting the system to restore the body balance when deviations from biological set points occur

Example Set pointsndash Blood sugar Hormone levels Temperature

Sodium34

Autonomic nervous system regulationInfluences PSNS through projections to brainstem

PSNS nuclei

Posterior area influences SNS through projections to the lateral gray horn

35

Hormone ProductionMagnocellular regions of the supraoptic and

paraventricular nuclei produce oxytocin and vassopressin (ADH)

Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700

Released in circulationDamage to supraoptic n diabetes insipidusrArr

36

Hormone Production

ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis

37

Cercadian rhythm regulation

ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland

38

Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills

Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating

39

Regulates Mechanism by

Receiving sensory information from all areas of the body

Comparing sensory information with biological set points

Adjusting the system to restore the body balance when deviations from biological set points occur

Example Set pointsndash Blood sugar Hormone levels Temperature

Sodium34

Autonomic nervous system regulationInfluences PSNS through projections to brainstem

PSNS nuclei

Posterior area influences SNS through projections to the lateral gray horn

35

Hormone ProductionMagnocellular regions of the supraoptic and

paraventricular nuclei produce oxytocin and vassopressin (ADH)

Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700

Released in circulationDamage to supraoptic n diabetes insipidusrArr

36

Hormone Production

ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis

37

Cercadian rhythm regulation

ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland

38

Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills

Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating

39

Autonomic nervous system regulationInfluences PSNS through projections to brainstem

PSNS nuclei

Posterior area influences SNS through projections to the lateral gray horn

35

Hormone ProductionMagnocellular regions of the supraoptic and

paraventricular nuclei produce oxytocin and vassopressin (ADH)

Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700

Released in circulationDamage to supraoptic n diabetes insipidusrArr

36

Hormone Production

ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis

37

Cercadian rhythm regulation

ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland

38

Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills

Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating

39

Hormone ProductionMagnocellular regions of the supraoptic and

paraventricular nuclei produce oxytocin and vassopressin (ADH)

Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700

Released in circulationDamage to supraoptic n diabetes insipidusrArr

36

Hormone Production

ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis

37

Cercadian rhythm regulation

ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland

38

Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills

Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating

39

Hormone Production

ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis

37

Cercadian rhythm regulation

ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland

38

Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills

Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating

39

Cercadian rhythm regulation

ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland

38

Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills

Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating

39

Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills

Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating

39