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1) Organization of the nervous system – axes and planes, CNS vs. PNS
2) Structure of spinal cord 3) Structure of brain4) Neurons and glial cells
Topic 1 – Neuroanatomy Review
1) Organization of the nervous system – axes and planes, CNS vs. PNS
2) Structure of spinal cord 3) Structure of brain4) Neurons and glial cells
Topic 1 – Neuroanatomy Review
CNS Organization - Axes
Fig. 1-1: Leonard, The Neuroscience of Human Movement, Mosby:Toronto, 1998.
dorsal
ventral
caudalrostral Alignment of quadruped brain and spine
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Alignment of human brain and spine
Fig. 1-9: Purves et al. Neuroscience, Sinauer Associates Inc: Massachusetts, 2001.
CNS Organization - Axes
Anterior (in front of; toward the front) Posterior
(behind; toward the back)
Inferior (below) Caudal
Superior (above)
Rostral
Caudal
Medial (middle)
Lateral (to the side)
Coronal Sagittal
Horizontal or Axial
CNS Organization - Planes
Fig. 1-9: Purves et al. Neuroscience, Sinauer Associates Inc: Massachusetts, 2001.
(Parasagittal)
CNS and PNS
• CNS – Central Nervous SystemConsists of the brain and spinal cord.
• PNS – Peripheral Nervous SystemConsists of the peripheral nerves and ganglia.
The CNS & PNS are separated anatomically but functionally interconnected.
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Source: Lundy-Ekman, Neuroscience: Fundamentals for Rehabilitation, Saunders, 2002
Afferent – carries info towards the CNSEfferent – carries info away from the CNS
1) Organization of the nervous system – axes and planes, CNS vs. PNS
2) Structure of spinal cord3) Structure of brain4) Neurons and glial cells
Topic 1 – Neuroanatomy Review
Spinal Cord• Segmented – each
segment has 1 pair of dorsal and ventral roots.
Source: Zigmond et al., Fundamental Neuroscience, Academic Press, 1999
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Source: Zigmond et al., Fundamental Neuroscience, Academic Press, 1999
Sensory IN(afferent)
Motor OUT(efferent)
Dorsal Horn
Ventral Horn
Source: Lundy-Ekman, Neuroscience: Fundamentals for Rehabilitation, Saunders, 2002
Gray matter –
Dorsal horn – groups of afferent sensory neurons from periphery
Ventral horn – groups of efferent motor neurons (cell bodies)
Also contains interneurons which modulate information flowing between the sensory and motor components
Source: Lundy-Ekman, Neuroscience: Fundamentals for Rehabilitation, Saunders, 2002
White matter –
Bundles of ascending and descending axons for carrying information towards and away from the brain
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1) Organization of the nervous system – axes and planes, CNS vs. PNS
2) Structure of spinal cord 3) Structure of brain4) Neurons and glial cells
Topic 1 – Neuroanatomy Review
Main regions of brainCerebellum – important for balance and coordination of movements
Source: MacKay, Neuro 101, Sefalotek Ltd., 1999 And Lundy-Ekman, Neuroscience: Fundamentals for Rehabilitation, Saunders, 2002
Cerebellar
hemisphere
Vermis
Main regions of brainMedulla – important role in regulation of critical cardiovascular and respiratory functions
Source: MacKay, Neuro 101, Sefalotek Ltd., 1999
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Main regions of brainPons – conveys information about movement from the cerebral hemispheres to the cerebellum
Source: MacKay, Neuro 101, Sefalotek Ltd., 1999
Main regions of brainMidbrain – important for coordination of visual and auditory reflexes
Source: MacKay, Neuro 101, Sefalotek Ltd., 1999
Main regions of brainDiencephalon –consists of
-Thalamus
-Hypothalamus
-Epithalamus
-Subthalamus
Source: MacKay, Neuro 101, Sefalotek Ltd., 1999
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Main regions of brainCerebral hemispheres
Source: MacKay, Neuro 101, Sefalotek Ltd., 1999 and Purves et al. Neuroscience, Sinauer Associates Inc: Massachusetts, 2001
Longitudinal fissureDorsal View
Left hemisphere
Right hemisphere
Gyrus
Sulcus
Subdivisions of Cerebral Cortex
Source: Lundy-Ekman, Neuroscience: Fundamentals for Rehabilitation, Saunders, 2002
Temporal lobe
Frontal lobe
Parietal lobe Occipital
lobe Frontal lobe
Parietal lobe
Occipital lobe
Temporal lobe
Source: Kandel et al., Principles of Neural Science, McGraw Hill, 2000
Functional Divisions of the Cortex (a few examples) -
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Anatomical divisions of the cortex -
e.g. Brodmann areas
Source: Mesulam M.-M., Principles of Behavioral and Cognitive Neurology, 2nd Ed. Oxford University Press, 2000
Brodmann areas are based on microscopic variations in neuronal architecture.
e.g.
A) prefrontal cortex
B) primary visual cortex
A B
There can be up to 6 different types of layers in the cortex:
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Cerebrospinal Fluid System
Source: Lundy-Ekman, Neuroscience: Fundamentals for Rehabilitation, Saunders, 2002
Ventricle
1) Organization of the nervous system – axes and planes, CNS vs. PNS
2) Structure of spinal cord 3) Structure of brain4) Neurons and glial cells
Topic 1 – Neuroanatomy Review
The nervous system is made up of two main categories of cells –
Neurons (nerve cells)
Glia (supporting cells)
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Neurons –
the excitable cells responsible for transmission of information in the nervous system.
Source: Kandel et al., Principles of Neural Science, McGraw Hill, 2000
4 main anatomical regions –-Soma (cell body)
-Dendrites
-Axon
-Presynaptic terminals
Axon Hillock
Presynapticterminals
1) Input
2) Integrative
3) Conductile
4) Output
4 common functional regions
Source: Kandel et al., Principles of Neural Science, McGraw Hill, 2000
Neurons come in many shapes and sizes…
Source: Purves et al. Neuroscience, Sinauer Associates Inc: Massachusetts, 2001.
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Sensory Motor Interneuron
Source: Kandel et al., Principles of Neural Science, McGraw Hill, 2000
Synaptic cleft
Source: Lundy-Ekman, Neuroscience: Fundamentals for Rehabilitation, Saunders, 2002
Neurotransmitters from the pre-synaptic terminal bind to receptors on a post-synaptic region
The nervous system is made up of two main categories of cells –
Neurons (nerve cells)
Glia (supporting cells)
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Two main types of glial cells -
1. Macroglia – large glial cells
2. Microglia – small glial cells
3 types of macroglia cells –1. Astrocytes
2. Oligodendrocytes
3. Schwann cells
Astrocytes- only found in the CNS
-main function is to maintain an appropriate chemical environment for neuronal signaling
- take up extra K+ ions, remove and metabolize chemical transmitters from synaptic cleft, remove debris
- important during development of CNS
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Astrocytes
Source: Kandel et al., Principles of Neural Science, McGraw Hill, 2000
-Part of the blood-brain barrier
-Provide lactate (‘fuel’) for neurons
3 types of macroglia cells –1. Astrocytes
2. Oligodendrocytes
3. Schwann cells
Oligodendrocytes and Schwann Cells
Schwann cells (PNS only)
Oligodendrocytes (CNS only)
Source: Kandel et al., Principles of Neural Science, McGraw Hill, 2000
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Two main types of glial cells -
1. Macroglia – large glial cells
2. Microglia – small glial cells
Microglia
-Scavenger cells that ingest foreign cells (e.g. bacteria) and old or injured cells.
-Increase in number after injury or disease
Proliferate from other microglia or from macrophages which migrate in from blood
End of Topic 1 – Neuroanatomy Review.