Nerve system 1. Classification of NS 2. CNS Brain: a) large hemispheres; b) cerebellum 3. Spinal cord 4. Meningeas 5. Blood-brain barrier 6. Peripheral nerve system. Spinal ganglia 7. Peripheral nerve 8. Nerve endings 9. Autonomic nerve system 10. 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 BRODMAN GRANULAR CORTEX – sensory (2nd, 4th) AGRANULAR CORTEX – motor (3rd,5th, 6)

CEREBELLUM Functions: 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

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 ORGANS EAR 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.Eye 2.Smell organ Secondary sensory Ear Taste buds Sensory endings (receptors) 1.Receptor of pain 2.Paccinian body 3.Bulb of Krause…

Organ of taste neuroepithelial cells supporting cells basal cells

AUDIOVESTIBULAR ORGAN (EAR) External ear Middle ear Internal ear

INTERNAL EAR vestibule+3 semicircular canals +cochlea Otolith membrane Hair cells Macula Maculae Organ of Corti Cristae ampullaris Tectorial membrane Hair cells Organ of Corti Crista ampullaris Hair cellsCupula Bony labyrinth Membranous labyrinth

Maculae

Crista ampullaris

Cochlea axial section Helicotrema Cochlear duct Scala vestibuli Modiolus Spiral ganglion Cohlear nerve Scala tympani

MEMBRANOUS LABYRINTH Cochlear duct

Membranous labyrinth (scheme) Vestibular membrane Basilar membrane Stria vascularis Scala vestibuli Cochlear duct Spiral ligament Stria vascularis Basilar membrane Scala tympani Vestibular membrane Tectorial membrane Spiral limbus Spiral tunnel Spiral bony lamella Cochlear nerve

Corti’s organ Hair cells Stria vascularis Basilar membrane Pillar cells Hensen cells Outer phalangeal 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 Outer supporting cells Betshar cells Inner phalangeal cells Basilar membrane Tectorial membrane Spiral tunnel Inner hair cells Inner border cells Inner tunnel Cochlear nerve Inner and outer pillar cells Outer phalangeal cells Outer hair cellsNerve fibers

Apical portion of outer phalangeal and hair cells 1 1.Stereocilia 2.Cuticula 3.Phalangeal processes 4.Hair cells bodies 2 3 4

Phalangeal and hair cells (scheme) Cuticular lamella Stereocilia Marginal network Afferent and efferent nerve fibers Phalangeal process Outer hair cell Outer phalangeal cell Basilar membrane

Hair cells stereocilia Basal body Stereocilia Excitation Apical junctions Cuticular lamella Microtubuli

Audiovestibular organ histophysiology Semicircular canals External auditory tube Tympanic membrane Eustachian tube Cochlea Scala vestibuli Scala tympani Cochlear duct Oval window Ampulae Endolymphatic sac Subarachnoidal space Endolymphatic duct Perilymphatic duct Processsus mastoideus Stapes Uncus Maleus

Hearing histophysiology Cochlear duct Tectorial membrane Organ of Corti Round window Basilar membrane Oval window Scala tympani Cochlear nerve Spiral ganglion Vestibular membrane Scala vestibuli