CEREBRAL cortex. Cortex of CEREBELLUM. SPINAL CORD. GANGLIA.
CEREBRAL cortex (=CC). Cortex corresponds to GRAY matter.
CC is composed of: a
) MULTIPOLAR NEURONs, b) GLIAL cs, including
protoplasmic ASTROCYTes, c) nerve FIBRes, d) capillaries.
Neurons are classified on 2 types:1)
PYRAMIDAL neurons (
85%), 2)
NONpyramidal neurons (15%).
NEURONs in CC form
6 layers:
-
MOLECULAR layer. Contains nonpyramidal neurons of Cajal.
-
External GRANULAR layer. Contains STELLATE neurons.
-
External PYRAMIDAL layer. Contains small- and medium-sized PYRAMIDAL neurons.
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Internal GRANULAR layer. Contains STELLATE neurons.
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GANGLIONIC layer (or internal PYRAMIDAL lay.). Contains LARGEST PYRAMIDAL neurons (80x120 micrometers). or BETZ cells. It send single axon to anterior horn of sp. cord gray matter and regulate voluntary contractions of skeletal muscles (motor function of Betz cs).Necrosis of BETZ cs leads to PARALYSIS (nonmotility) of extremities.
-
The MULTIFORM layer. Contains nonpyramidal Martinotti neurons.
Cortex of CEREBELLUM. (=CCE):
CCE is composed of: a
) multipolar NEURONs, b) GLIAL cs, c) nerve FIBRes , d) capillaries.
NEURONs in CCE form
3 layers:
-
MOLECULAR layer. Contains: a) stellate neurons, b) basket neurons
-
GANGLIONIC layer (or PURKINJE cells layer). Contains FLASK-shaped PURKINJE cells. In real microslide Purkinje cs are located in SINGLe row. Function of CEREBELLUM and function of PURKINJE cells is SAME: regulation of body BALANCE, COORDINATION and PRECISE movements. Axons of Purkinje cs leave cortex and form single type of EFFERENT nerve fibres in CCE.
-
GRANULAR layer. Contains: a) granule neurons, b) bid granule neurons (or GOLGI cells), c)cerebellar glomeruli (compound synapse with incoming afferent MOSSY fibres).
SPINAL CORD.
On the cross section it has: 1)
GRAY
matter (=
GM) – it is inside, 2) WHITE matter – peripherally.
GM is composed of: a
) MULTIPOLAR NEURONs, b) GLIAL cs, including
protoplasmic ASTROCYTes and
ependymal cells, c) nerve FIBRes .
GM has
4 portions
: 1) Dorsal horn, 2) Ventral horn, 3) Lateral horn, 4) Central canal.
Dorsal HORN of
GM contains 4 nuclei: a) nucl. thoracicus, b) nucl. proper, c) substantia gelatinosa, d) subst. spongiosa. Nuclei are composed of
INTERNEURONS (it are
2nd neuron of SOMATIC reflex arch).
Dorsal ROOT of
spinal NERVE enters into dorsal HORN. Dorsal ROOT of
spinal nerve is formed by axons of PSEUDOUNIPOLAR SENSORY neurons of dorsal root GANGLION.
Ventral HORN of GM contains MOTOR nuclei. It are composed of MOTOR neurons (
3rd neuron of SOMATIC reflex arch). Axons of it are terminated on skeletal muscles.
Lateral HORN of
GM contains lateral and medial nuclei. Both contains INTERNEURONS of AUTONOMIC reflex arch. Axons of it are terminated in AUTONOMIC GANGLIA.
Ventral (anterior) ROOT of
spinal NERVE leaves ventral horn. Ventral ROOT of
spinal nerve is formed by : a)
axons of interneurons of lateral horn and b)
axons of motor neurons of ventral horn.
Wall of
central CANAL is lined by
EPENDYMAL cs. It are cuboidal cells with apical CILIA. Funct.: it participate in
movement of CEREBROSPINAL
fluid.
Embryonic
origin for NEURONs of
CNS (cerebral cortex, cortex of cerebellum, spinal cord) – are neuroblasts of
MANTLE zone of NEURAL
TUBE.
DORSAL ROOT GANGLION. ( it located in dorsal root of spinal nerve).
Structure: 1) Connective tissue
capsule surrounds ganglion, 2) Perikaryons of
PSEUDOUNIPOLAR SENSORY neurons located bellow the capsule.3) Neurons are surrounded by glial
satellite cs, 4) Central part of ganglion contains nerve FIBRES.
Dendrite directs on periphery (in skin) and forms RECEPRORs.
AXON directs in dorsal horn and participates in formation of
dorsal ROOT of
spinal NERVE.
Embryonic
origin for PSEUDOUNIPOLAR neurons of this GANGLION – are neuroblasts of neural
CREST.
Составитель – доцент В.В. Бондаренко.
