nerve system 1. classification of ns 2. cns brain: a) large hemispheres; b) cerebellum 3. spinal...

Nerve system1. Classification of NS 2. CNS Brain:

a) large hemispheres;b) cerebellum

3. Spinal cord4. Meningeas5. Blood-brain barrier6. Peripheral nerve system. Spinal ganglia7. Peripheral nerve8. Nerve endings9. Autonomic nerve system10. Simple reflex arc

Nervous system – special highly organized system (nervous tissue + connective)– intercommunicating network of neurons

CLASSIFICATION

• Anatomical (structural):

• central nervous system (CNS) – brain and spinal cord;

• peripheral (PNS) – endings, fibers, ganglia, plexuses.

• Functional:

• a) somatic (voluntary, animal);

• b) autonomic (involuntary, vegetative)

• FUNCTIONS• 1. Integration• 2. Control • 3. Regulation• 4. Reception• 5. Conduction • 6. Analysis • 7. Response

• NERVOUS SYSTEM ORIGIN• Ectoderm - nerve tube and ganglious lamella.

• Cranial portion of nerve tube – brain and sense organs• Middle part of nerve tube and ganglious lamella– spinal cord, dorsal-

root ganglia (spinal ganglia), autonomic ganglia and chromaffin tissue of human body.

• Nervous tube zones• Ependymal – precursors of glial ependymal cells• Mantial layer – neuroblasts (nerve cells) and spongyoblasts (astrocytes

and oligodendrocytes)• Marginal Zone – processes

BRAIN• Histologically:grey matter (nerve cells body) • white matter ( nerve fibers)

• Grey matter: cortex + subcortical nuclei

• MODUL – MFU of brain cortex • cilinder d 300 mkm around cortico-cortical fiber• NEUROPIL – aggregations of nerve and glial cells processes

in central nerve system

• Cytoarchitectonics - well regulated location of nervous cells (6 layers)

• Myeloarchitectonics - well regulated location of nervous fibers (4 layers)

Cytoarchitectonics

• Brain cortex has 6 layers• Pyramidal cells in the 2nd, 3rd, 4th, 5th layers

• 1. Molecular

• 2. Outer granular (10mkm)

• 3. Pyramidal (10-40mkm)

• 4. Inner granular

• 5. Ganglionic (120x80, Betz, 1874)

• 6. Multiform

MYELOARCHITECTONICS

• 1. Above the 1st layer• 2. Under the 1st layer• 3. Above the 5th layer• 4. Under the 5th layer

• TYPES OF NERVE FIBERS• Associative• Comissural• Projective

52 FIELDS OF BRODMANGRANULAR CORTEX –

sensory (2nd , 4th)AGRANULAR CORTEX –

motor (3rd,5th, 6)

CEREBELLUMFunctions: 1. Coordination 2. Movement 3. Balance 4. Muscle tonus

• Molecular layer: basket cells • large stellate cells• small stellate cells• Purkinje cells layer: Purkinje cells, supporting cells

(lophogliocytes)• Granular layer: corn cells• stellate cells (2types) horizontal cells• Afferent fibers:• Mosslike– from olives and pons to the corn cells (tr.

olivocerebellaris, tr. pontocerebellaris)• Climbing–from spinal cord and vestibular nuclei to the Purkinje

cells (tr. spinocerebellaris, tr. vestibulocerebellaris)• Efferent fibers: axons of Purkinje cells

CEREBELLUM

Spinal cord

MENINGES

MENINGES• 3 protective coats of CNS: dura, arachnoid and pia mater

• Skull bone• Periosteum of skull• epidural space• 1. DURA MATER – dense connective tissue• epithelium• subdural space• 2. ARACHNOID – flat epithelium• fibrocollagenous tissue• web-like strands• subarachnoid space• 3. PIA MATER – squamous epithelium• – loose connective tissue with blood vessels and nerve

fibers• Basement membrane• Glia limitans (astrocytes)• Nerve tissue

BLOOD-BRAIN BARRIER

• Prevents diffusion of substances from the blood to the brain

• Capillary wall • 1. Endothelium• 2. Basement membrane

• 3. Glial sheath (foot processes of astrocytes)

Peripheral nerve

Peripheral nerve ultrastructure

AUTONOMIC NERVE SYSTEM• Anatomically: a) central • b) peripheral• Functionally: a) sympathetic

b) parasympathetic

• SYMPATHETIC NS• Centers: thoracic-lumbar disposition• Nuclei intemediolateralis of spinal cord – multipolar associative

radicular neurons• Sympathetic ganglia: paravertebral (trunci simpatici) and prevertebral

(3)

• PARASYMPATHETIC NS• Centers: cranio-sacral disposition• Nuclei of cranial nerves III, VII, IX and X pairs • Extramural and intramural ganglia (Dogel cells)

Autonomic nerve system

Autonomic ganglion

Reflex arc

SENSE ORGANSEAR

1. Taste buds

2. Audiovestibular analizator

3. Audiovestibular organ

4. External ear

5. Middle ear

6. Internal ear:

a) bony labyrinth;

b) membranous labyrinth

7. Hair cells

8. Audiovestibular organ histophysiology

ANALIZATOR sense organ + nerve + cortex (field)

Sense organs

Primary sensory

1. Eye2. Smell organ

Secondary sensory

EarTaste buds

Sensory endings (receptors)

1. Receptor of pain2. Paccinian body3. Bulb of Krause…

Organ of taste

neuroepithelial cells supporting cellsbasal cells

AUDIOVESTIBULAR ORGAN (EAR)

External ear

Middle ear

Internal ear

INTERNAL EARvestibule+3 semicircular canals

+cochlea

Otolithmembrane

Hair cells

Macula

Maculae

Organ of Corti

Cristae ampullaris

Cristae ampullaris

Tectorial membrane

Hair cells

Organ of Corti Crista ampullaris

Hair cellsCupula

Bony labyrinthMembranous labyrinth

Maculae

Crista ampullaris

Cochlea axial section

• Helicotrema

Cochlear duct

Scala vestibuliModiolus

Spiral ganglion

Cohlear nerve

Scala tympani

MEMBRANOUS LABYRINTH

• Cochlear duct

Membranous labyrinth (scheme)

• Vestibular membrane• Basilar membrane• Stria vascularisScala vestibuli

Cochlear duct Spiral ligament

Stria vascularis

Basilarmembrane

Scala tympani

Vestibular membrane

Tectorial membraneSpiral limbusSpiral tunnelSpiral bony lamella

Cochlear nerve

Corti’s organHair cellsStria vascularis

Basilarmembrane

Pillar cells

Hensen cells

Outerphalangeal cells

Corti’s organ Outer cells: A. Supporting 1. Phalangeal (Deyters)

2. Border (Hensen) 3. Outer supporting (Claudius)

B. Hair cells (3-5)Tunnel (pillar cells)Inner cells A. Supporting 1. Phalangeal

2. Inner supporting B. Hair cells (1-2)

Outer border cells

Outersupporting cells

Betsharcells

Inner phalangeal cells

Basilar membrane

Tectorial membrane Spiral tunnel Inner hair cells Inner border cells

Inner tunnel

Cochlear nerve

Inner and outer

pillar cellsOuter

phalangealcells

Outer hair cells Nerve fibers

Apical portion of outer phalangeal and hair cells

1

1. Stereocilia2. Cuticula3. Phalangeal processes4. Hair cells bodies

2

3

4

Phalangeal and hair cells (scheme)

Cuticularlamella

Stereocilia

Marginalnetwork

Afferentand efferentnerve fibers

Phalangealprocess

Outer hair cell

Outerphalangeal cell

Basilarmembrane

Hair cells stereocilia

Basal body

Stereocilia

Excitation

Apicaljunctions

Cuticular lamella

Microtubuli

Audiovestibular organ histophysiology

Semicircularcanals

Externalauditory tube

Tympanic membrane

Eustachian tubeCochlea

Scala vestibuli

Scala tympani

Cochlear ductOval window

Ampulae Endolymphatic sac

Subarachnoidal space

Endolymphatic duct

Perilymphatic duct

Processsusmastoideus Stapes

UncusMaleus

Hearing histophysiology

Cochlear duct

Tectorial membrane

Organ of CortiRoundwindow

Basilarmembrane

Ovalwindow

Scala tympaniCochlear

nerve Spiralganglion

Vestibular membrane

Scala vestibuli