INTRODUCTION TO NERVOUS SYSTEM CELLS IN NERVOUS SYSTEM HISTOLOGY OF PERIPHERAL NERVE HISTOLOGY OF GANGLIA FEW CLINICAL ASPECT

1. NERVOUS TISSUE
HISTOLOGY PART 1
DR ANTONY JOSEPH MBBS MD

2. BRIEF INTRODUCTION TO
NERVOUS SYSTEM
CELLS IN NERVOUS
SYSTEM
HISTOLOGY OF
PERIPHERAL NERVE
HISTOLOGY OF
SYMPATHETIC & SPINAL
GANGLION

3. NERVOUS TISSUE - INTRODUCTION
ONE OF THE 4 BASIC
TISSUES IN THE BODY
4 BASIC TISSUES IN
THE BODY
EPITHELIAL TISSUE
CONNECTIVE TISSUE
NERVOUS TISSUE
MUSCULAR TISSUE

4. FUNCTIONS
COORDINATING &
CONTROLLING MANY
BODY ACTIVITIES
STIMULATE MUSCLE
CONTRACTION
CREATES AWARENESS OF
THE ENVIRONMENT
MAJOR ROLE IN
EMOTIONS, MEMORY &
REASONING
NERVOUS TISSUE - INTRODUCTION

5. NERVOUS TISSUE - INTRODUCTION
CLASSIFICATION
ANATOMICAL
CLASSIFICATION
FUNCTIONAL
CLASSIFICATION

6. NERVOUS TISSUE - INTRODUCTION
ANATOMICAL CLASSIFICATION OF NERVOUS TISSUE
CENTRAL NERVOUS SYSTEM
BRAIN & SPINAL CORD
PERIPHERAL NERVOUS SYSTEM
• 12 PAIRS OF CRANIAL NERVES ARISING
FROM THE BRAIN
• 31 PAIRS OF SPINAL NERVES ARISING
FROM THE SPINAL CORD &
ASSOCIATED GANGLIA

7. NERVOUS TISSUE - INTRODUCTION
FUNCTIONAL CLASSIFICATION OF NERVOUS TISSUE
AFFERENT DIVISION /
SENSORY
BRINGS INFORMATION TO CNS
EFFERENT DIVISION /
MOTOR
GIVES MOTOR COMMANDS TO MUSCLES AND GLANDS
SOMATIC NERVOUS SYSTEM
INNERVATE SOMATIC
STRUCTURES LIKE MUSCLES –
RESPONSIBLE FOR VOLUNTARY
MOTOR ACTIVITIES.
AUTONOMIC NERVOUS SYSTEM
INNERVATE VISCERAL STRUCTURES
LIKE CARDIAC MUSCLES, SMOOTH
MUSCLES & GLANDS – RESPONSIBLE
FOR INVOLUNTARY ACTIVITIES
SUBDIVIDED INTO SYMPATHETIC AND
PARASYMPATHETIC

8. NERVOUS TISSUE - INTRODUCTION
MOTOR
NEURONS ARE
MULTIPOLAR
NEURONS.
SENSORY
NEURONS ARE
PSEUDO –
UNIPOLAR
NEURONS.

10. SOMATIC NERVOUS SYSTEM
THIS DEALS WITH THE CHANGES IN THE EXTERNAL
ENVIORNMENT – EXTEROCEPTION OR PROPRIOCEPTION AND
GIVES A RESPONSE BY REFLEX ACTIVITIES WHICH ARE GENERALLY
EXPRESSED BY THE MOVEMENT OF SKELETAL MUSCLES OR BY
ALTERATION OF EMOTIONAL BEHAVIOUR. SOMATIC NERVOUS
SYSTEM INNERVATES SOMATIC STRUCTURES LIKE MUSCLES –
RESPONSIBLE FOR VOLUNTARY MOTOR ACTIVITIES.

12. KNEE JERK IS
PRODUCED BY
SOMATIC
NERVOUS SYSTEM

14. THREE TYPE OF NEURONS IN
SOMATIC NERVOUS SYSTEM
A SENSORY NEURON – PSEUDO-UNIPOLAR
NEURON IN DORSAL ROOT GANGLION IN
SPINAL NERVE.
A CONNECTOR – INTERNEURON IN THE
GREY COLUMN OF THE SPINAL CORD.
AN EFFECTOR – MOTOR NEURON –
MULTIPOLAR NEURON IN THE ANTERIOR
GREY COLUMN OF THE SPINAL CORD.

16. THE MOTOR RESPONSE OF THE
SOMATIC NERVOUS SYSTEM MAY BE
REFLEXLY ORIENTED OR MEDIATED
UNDER VOLUNTARY CONTROL.

17. VOLUNTARY ACTION
IS CONTROLLED BY
BRAIN. IT REQUIRES
THINKING. THUS IT IS
SLOWER. SUITABLE
FOR EVERDAY
ACTION.
INVOLUNTARY
ACTION IS USALLY
CONTROLLED BY
SPINAL CORD. TAKES
PLACE WITHOUT
THINKING. IT IS FAST
AND RAPID. ALSO LIFE
SAVING ACTION.

18. AUTONOMIC NERVOUS SYSTEM
IT DEALS WITH THE CHANGES IN THE INTERNAL ENVIRONMENT
AND GIVES A RESPONSE BY REFLEX ACTIVITIES TO MAINTAIN CONTANT
INTERNAL ENVIORNMENT. AUTONOMIC NERVOUS SYSTEM REGULATES
THE BODY TEMPERATURE, BLOOD PRESSURE, CARDIO-RESPIRATORY
RATE, GASTO-INTESTINAL MOTILITY AND GLANDULAR SECRETION.
IT INNERVATE VISCERAL STRUCTURES LIKE CARDIAC MUSCLES, SMOOTH
MUSCLES & GLANDS – RESPONSIBLE FOR INVOLUNTARY ACTIVITIES.
SUBDIVIDED INTO SYMPATHETIC AND PARASYMPATHETIC

19. THE AUTONOMIC SYSTEM HAS BOTH SENSORY AND MOTOR COMPONENTS.
THE MOTOR COMPONENT HAS TWO SET OF NEURONS. PREGANGLIONIC AND
POSTGANGLIONIC NEURONS.

23. PARASYMPATHETIC PATHWAYS

24. SYMPATHETIC PATHWAYS

29. THE RECEPTOR OR TARGET CELLS SUPPLIED
BY POSTGANGLIONIC MOTOR NEURONS ARE
OF THREE TYPES – CARDIAC MUSCLE,
SMOOTH MUSCLE & GLANDULAR CELL.

30. NEURON
NEURONS ARE THE
STRUCTURAL AND
FUNCTIONAL UNITS
OF A NERVOUS
SYSTEM

31. CELL BODY
PROCESSES: ONE OR MORE DENDRITES
AND A SINGLE AXON.

32. CELL BODY / SOMA /
PERIKARYON
CELL BODIES ARE
MOSTLY SITUATED IN THE
GREY MATTER OF THE
BRAIN AND THE SPINAL
CORD. ALSO FOUND IN
DORSAL ROOT GANGLIA.

33. THE CELL MEMBRANE OF THE
CELL BODY IS TRILAMINAR –
HAS 3 LAYERS. OUTER AND
INNER PROTEIN LAYER. MIDDLE
BIMOLECULAR LIPID LAYER.
NUCLEUS IS IN THE CENTER.
LARGE AND CONTAIN
PROMINENT NUCLEOLUS.

34. IN CASE OF INJURY OR
FATIGUE OF THE NERVE
CELL, THE NUCLEUS WILL BE
ECCENTRIC IN POSITION.
HOWEVER IN HEALTHY
SYMPATHETIC GANGLION
CELLS HAS ECCENTRIC
NUCLEUS.
IN FEMALES, BARR BODY IS
PRESENT BENEATH THE
NUCLEAR MEMBRANE.

37. THE CYTOPLASM OF THE
CELL BODY HAS
FOLLOWING
STRUCTURES:
NISSL SUBSTANCE
GOLGI COMPLEX
MITOCONDRIA
NEUROFIBRILS
NEUROFILAMENTS
MICROTUBULES
LYSOSOMES
LIPOFUSIN
MELANIN GRANULES
ETC

40. NISSL SUBSTANCE ARE
GRANULES THAT ARE
DISTRIBUTED THROUGHOUT
THE CYTOPLASM OF THE CELL
BODY EXCEPT IN THE REGION
CLOSE TO AXON – AXON
HILLOCK. NISSLE GRANULES
ARE COMPOSED OF ROUGH
ENDOPLASMIC RETICULUM.
THEY ARE RESPONSIBLE FOR
PROTEIN SYNTHESIS.

41. CHROMATOLYSIS is a cell body
reaction to neuronal injury, such
as mechanical injury or by toxic
agents. Features of neuron
chromatolysis include a swollen
cell body, eccentric nucleus, and
loss of Nissl substance except
along the margins of the cell
body. Chromatolysis is
reversible, if the normal
condition is restored within
reasonable time. PICS: Two
chromatolytic cell bodies (C) are
adjacent to a normal cell body (N).

42. NEUROFIBRILS : THESE
ARE ULTRAMICROSCOPIC
FINE FIBRILS, ARRANGED IN
A PLEXIFORM MANNER IN
THE CELL BODY AND EXTEND
IN ALL PROCESSES.
NEUROFIBRILS ARE
CROWDED TOGETHER IN
AXON HILLOCK.
THESE FIBRILS ACT AS
INTERNAL SUPPORT OF THE
NEURONS BUT DO NOT HELP
IN THE CONDUCTION OF THE
NERVE IMPULSE.

43. DENDRITES ARE THE
SHORT PROCESSES OF THE CELL
BODIES. THEY BRANCHES
PROFUSELY.
CYTOPLASM OF THE DENDRITES
CLOSELY RESEMBLES THAT OF
CELL BODIES AND CONTAIN NISSL
GRANULES, MITOCHONDRIA,
MICROTUBULES ETC.
DENDRITES SHUD BE REGARDED
AS AN EXTENSION OF THE CELL
BODY. THEY CONDUCT IMPULSE
TOWARDS THE CELL BODY.

44. NUMEROUS THORN-LIKE
DENDRITIC SPINES KNOWN AS
GEMMULES PROJECT FROM
THE TERMINAL BRANCHES OF
DENDRITES.
THESE DENDRITIC SPINES
INCREASE THE AREA OF
CONTACT WITH THE AXONS OF
THE ADJACENT NEURONS AT
THE SYNAPTIC JUNCTION.

45. Dendritic spines are a
preferential site of synaptic
axodendritic contact; they
are sparse or absent in
some types of nerve cells
(motor neurons, the large
cells of the globus pallidus,
and stellate cells of the
cerebral cortex), and
exceedingly numerous in
others such as the
pyramidal cells of the
cerebral cortex and the
Purkinje cells of the
cerebellar cortex.

46. Dendritic spines are known to
change shape, to the extend of
appearing and disappearing
entirely. It has long been
hypothesised that such changes
may be the basis of learning and
memory formation itself.
Dysregulation of spine
morphology is seen in several
neurological disorders such as
Alzheimer’s disease and fragile
X syndrome.

47. AXON

49. AXON
LONGEST PROCESS OF THE CELL
BODY. ARISE FROM THE AXON
HILLOCK. THEY ARE DEVOID OF
NISSL GRANULES. AXON IS
TUBULAR AND UNIFORM IN
DIAMETER. DISTAL ENDS OF THE
TERMINAL BRANCHES ARE
ENLARGED KNOWN AS
TERMINALS.

50. PLASMA MEMBRANE
OF AXON IS CALLED
AXOLEMMA. THE
CYTOPLASM OF AXON
IS CALLED AXOPLASM.
AXOPLASM HAS NO
NISSL GRANULES AND
GOLGI COMPLEX.

51. MICROTUBULES,
NEUROFILAMENTS,
MITOCHONDRIA PASS
THROUGH THE AXON
HILLOCK INTO THE AXON.
THE ORGANIZATION AND
ARRANGMENT OF
MICROTUBULES IN AXONS
AND DENDRITES ARE
UNIQUE AND CRITICAL FOR
THE FUNCTIONAL POLARITY
OF NEURONS.

52. FROM THE SIDE OF THE AXON, AT NODE OF RANVIER, A
NUMBER OF COLLATERAL BRANCHES MAY ARISE AT
RIGHT ANGLES.

53. CLOSE TO THE TERMINATION, THE AXONS DIVIDES INTO SMALLER BRANCHES
KNOWN AS TELODENDRIA.

54. AT SYNAPSE, TELODENDRIA FORM SMALL BULBOUS
SWELLINGS CALLED BOUTONS TERMINAUX.

55. THE SYNAPSE
SYNAPSES ARE SPECIALIZED
JUNCTION BETWEEN TWO
OR MORE ADJACENT
NEURONS.
BOUTONS TERMINAUX OF
ONE NEURON COME IN
CONTACT WITH DENDRITES
OR CELL BODY OF OTHER
NEURON.

56. COMPONENTS OF A
SYNAPSE
PRESYNAPTIC MEMBRANE
SYNAPTIC CLEFT
POSTSYNAPTIC MEMBRANE

57. TYPES

58. SYNAPSE CLASSIFICATION BASED
ON THE ULTRASTRUCTURE Asymmetric synapses
include axons that contain
predominantly round or
spherical vesicles and
form synapses that are
distinguished by a
thickened, postsynaptic
density. In contrast,
Symmetric synapses
involve axons that contain
clusters of vesicles that
are predominantly
flattened or elongate in
their appearance. The
pre-and postsynaptic
membranes are more
parallel than the
surrounding nonsynaptic
membrane, and the
synapse does not contain
a prominent postsynaptic
density.

60. CELLS IN THE
NERVOUS
SYSTEM
NEURONS NEUROGLIA
ACCORDING TO POLARITY
• UNIPOLAR
• BIPOLAR
• PSEUDO UNIPOLAR
• MULTIPOLAR
ACCORDING TO FUNCTION
• SENSORY/RECEPTOR
NEURON
• INTERNUNCIAL NEURON
• MOTOR OR EFFECTOR
NEURON
ACCORDING TO THE
RELATIVE LENGTHS OF
AXONS & DENDRITES
• GOLGI 1 TYPE
• GOLGI 2 TYPE

61. CLASSIFICATION ACCORDING TO POLARITY

62. UNIPOLAR
NEURON
NEURONS FIRST DEVELOP
AS UNIPOLAR CELLS AND
SEND OUT A SINGLE
PROCESS.
MESENCEPHALIC NUCLEUS OF
TRIGEMINAL NERVE IS
CONSIDERED AS UNIPOLAR
NEURON.

63. BIPOLAR
NEURON
OLFACTORY CELLS OF NASAL MUCOUS
MEMBRANE, SOME CELLS OF RETINA AND
GANGLION CELLS OF AUDITORY NERVE ARE
BIPOLAR NEURONS

64. PSEUDO UNIPOLAR
NEURON
BIPOLAR NEURONS FURTHER
DIFFERENTIATE TO FORM
PSEUDO UNIPOLAR NEURON.
IT POSSESS A SINGLE PROCESS
BIFURCATING IN A ‘T’ SHAPED
MANNER.
NEURONS OF DORSAL ROOT GANGLIA OF
ALL SPINAL NERVES AND SENSORY GANGLIA
OF SOME CRANIAL NERVES ARE PSEUDO
UNIPOLAR

65. MULTIPOLAR
NEURONS
MOST OF THE NEURONS IN THE BODY IS OF THIS TYPE

66. CLASSIFICATION OF
NEURONS ACCORDING TO
FUNCTION
• SENSORY/RECEPTOR NEURON
• INTERNUNCIAL
NEURON/INTERNEURON
• MOTOR OR EFFECTOR
NEURON

67. CLASSIFICATION OF
NEURON ACCORDING TO
THE RELATIVE LENGTHS
OF AXONS & DENDRITES
• GOLGI 1 TYPE
• GOLGI 2 TYPE
GOLGI 1 TYPE NEURONS: DENDRITES ARE SHORT AND
NUMEROUS. AXONS ARE LONG – CAN REACH UPTO 2 FEET IN
LENGTH. THESE NEURONS FORMS TRACTS OF CNS OR
TERMINATES AS PERIPHERAL NERVE.
GOLGI 2 TYPE NEURONS: AXONS ARE SHORT AND
MORPHOLOGICALLY SIMILAR TO DENDRITES. THEY ARE
CONFIRMED WITHIN THE GREY MATTER AND ESTABLISH
SYNAPTIC CONNECTIONS WITH OTHER NEURONS.

68. NEUROGLIA
• SUPPORTING CELLS
• NON-EXCITABLE CELLS
• UNDERGOES MITOTIC DIVISION
FUNCTIONS
• PROVIDES STRUCTURAL SUPPORT
• ACTIVELY TAKEPART IN IONIC TRANSPORT
• HELPS IN METABOLISM OF BRAIN
• PROCESSES OF SOME
NEUROGLIA FORM GLIAL
MEMBRANE BETWEEN BLOOD
VESSELS & NEURONS
• THE NUMBER OF NEUROGLIAL
CELLS ARE 10 TIMES MORE
THAN THE NUMBER OF
NEURONS.
• NEUROGLIAL CELLS
CONSTITUTES HALF OF THE
BRAIN VOLUME.
1
3
2
4

69. CELLS IN THE
NERVOUS
SYSTEM
NEURONS NEUROGLIA
CENTRAL
NEUROGLIA
PERIPHERAL
NEUROGLIA
MORPHOLOGICALLY AND
FUNCTIONALLY SIMILAR TO
ASTROCYTES. THEY RESIDES
WITHIN THE WALL OF THE
INTESTINAL TRACT. REGULATES
GASTROINTESTINAL MOTILITY.
SCHWANN CELL
SATELLITE CELL
MACROGLIA
ASTROCYTES
OLIGODENDROCYTES
EPENDYMAL CELLS
MICROGLIA
ENTERIC
NEUROGLIA
1 2 3

70. SCHWANN CELL
PRODUCE &
MAINTAIN MYLEIN
SHEATH

71. PROCESS OF MYELINATION

73. PROCESS OF
MYELINATION
THE PROCESS STARTS
BEFORE BIRTH &
CONTINUE TILL AGE ONE.
AS THE AXON SINKS INTO
THE SCHWANN CELL, THE
EXTERNAL PLASMA
MEMBRANE OF
SCHWANN CELL FORMS A
MESAXON.
AS THE AXON SUSPENDS WITHIN
THE SCHWANN CELL, THE
SCHWANN CELL ROTATES SO THAT
THE PLASMA MEMBERANE WRAPS
AROUND THE AXON IN A SPIRAL
MANNER. SOME NERVE FIBERS
ARE ONLY SURROUNDED BY FEW
MEMBRANE, OTHERS UPTO 50
TURNS.
1
2
3

74. THE MYELINATION BEGINS WHEN A SCHWANN CELL
SURROUNDS THE AXON AND ITS CELL MEMBRANE
BECOME POLARIZED.
THE THICKNESS OF THE MYELIN SHEATH IS DETERMINED
BY AXON DIAMETER AND NOT BY SCHWANN CELL.
NODE OF RANVIER IS THE JUNCTION BETWEEN TWO
SCHWANN CELL.

75. SCHWANN CELL &
UNMYELINATED
AXONS

76. MYELINATED VS
UNMYELINATED
NERVE FIBERS

77. OLIGODENDROCYTES
OLIGODENDROCYTES
PRODUCE AND MAINTAINS
MYLEIN SHEATH IN CNS

78. OLIGODENDROCYTES
SMALLER THAN ASTROCYTES. FOUND IN BOTH GREY &
WHITE MATTERS. EACH CELLS HAS DEEPLY STAINED OVAL &
ECCENTRIC NUCLEUS. SCANTY CYTOPLASM. LESS BRANCHED
THAN ASTROCYTES.
THREE TYPES OF OLIGODENDROCYTES:
• PERI-NEURAL SATELLITE CELLS - FOUND IN
GREY MATTER, ARRANGED AROUND THE
PERIPHERY OF THE CELL BODY &
DENDRITES.
• PERI-FASCICULAR CELLS – FOUND IN WHITE
MATTER. ARRANGED IN ROWS ALONG THE
MYELINATED NERVE FIBERS.
• JUXTA-VASCULAR CELLS – SURROUNDS THE
BLOOD VESSELS. CONTROL BLOOD FLOW.

79. OLIGODENDROCYTE
FUNCTIONS
FORMATION AND MAINTANCE OF MYLEIN
SHEATH. A SINGLE OLIGODENDROCYTES CAN
DEPOSIT MYLEIN OVER 3 DOZEN AXONS.
COMPAIRED TO SCHWANN CELL IT DEPOSIT
MYLEIN ONLY IN ONE AXON
PROVIDE ENERGY TO NEURONS & HELP IN
NEURONAL METABOLISM
OLIGODENDROCYTES & SCHWANN CELLS
CONTRACT RHYTHMICALLY – HELPS IN
AXOPLASMIC FLOW
1
3
2

81. ASTROCYTES
LARGEST OF NEUROGLIAL
CELLS.
SMALL CELL BODIED WITH
BRANCHING PROCESSES IN ALL
DIRECTION.
TWO TYPES
PROTOPLASMIC ASTROCYTES
FIBROUS ASTROCYTES

82. FIBROUS ASTROCYTES
HAS LONGER AND THINNER
PROCESSES. MICROFILAMENTS
KNOWN AS GLIOFIBRILS ARE
PRESENT IN THE PROCESSES.
THEY ARE PRESENT IN THE
WHITE MATTER.
PROTOPLASMIC ASTROCYTES
HAS NUMEROUS SHORT AND
THICK PROCESSES. GLIOFIBRILS
ARE ABSENT. THEY ARE
PRESENT IN GREY MATTER.

83. AT THE OUTER AND INNER
SURFACES OF CNS, THE PROCESSES
OF ASTROCYTES ARE INTERWOVEN
TO FORM OUTER AND INNER GLIAL
LIMITING MEMBRANE.
OUTER : PIA-GLIAL MEMBRANE :
PIA MATTER + ASTROCYTES.
INNER : EPENDYMAGLIAL
MEMBRANE : OVER THE LINING OF
VENTRICLES & CENTRAL CANAL OF
SPINAL CORD.

85. ASTROCYTES FUNCTION BLOOD BRAIN BARRIER (BBB)
RETRIEVE NEUROTRASMITTERS LIKE GABA,
GLUMATE AFTER THE RELEASE FROM THE
NERVE ENDING
REDUCE THE POTTASIUM CONCENTRATION
IN THE EXTRACELLULAR AREA. LOW K+ IS
ESSENTIAL FOR NEURONAL ACTIVITIES.
ASTROCYTES ARE THE PRIMARY GLYCOGEN
STORE HOUSE IN THE CNS
1
2
4
3

86. THE BLOOD BRAIN BARRIER (BBB)
CONSIST OF:
• ENDOTHELIUM OF CAPILLARIES
WHICH ARE NON-FENESTRATED
& CONTINOUS CONNECTED BY
TIGHT JUNCTION.
• SUBSTANTIAL BASEMENT
MEMBRANE UPON WHICH THE
ENDOTHELIUM RESTS.
• PERIVASCULAR FOOT AND CELL
BODIES OF ASTROCYTES.

88. 88% OF THE BASEMENT
MEMBRANE IS COVERED BY
PERIVASCULAR FOOT &
CELL BODY OF ASTROCYTES.
4% BY THE PROCESSES OF
OLIGODENDROCYTES.
REST 8% BY THE PROCESSES
OF UNDETERMINED CELLS.

89. BLOOD BRAIN BARRIER (BBB)
CONVEYS NUTRITION TO THE
NEURONS, PERMITS DIFFUSION
OF WATER, OXYGEN AND CO2
READILY.
BUT RESTRICTS THE PASSAGE
OF MACROMOLECULES OF
PROTEINS, BILE SALTS &
CATECHOLAMINES TO THE
BRAIN CELLS

90. EPENDYMAL CELLS
THESE ARE EPITHELIAL LIKE LINING OF THE
FLUID FILLED CAVITIES OF THE CNS. THEY
FORM A SINGLE LAYER OF CUBOIDAL TO
COLUMNAR CELLS.
THE APICAL SURFACE OF CELLS HAS CILLIA
& MICROVILLI.
THE BASAL SURFACE HAS NUMEROUS
INFOLDINGS THAT INTERDIGITATE WITH
ADJACENT ASTROCYTE PROCESSES.

91. SPINAL CORD WITH
CENTRAL CANAL

92. EPENDYMAL CELLS ARE OF 3 TYPES:
• EPENDYMOCYTES : LINES VENTRICLES OF
BRAIN AND SPINAL CORD.
• TANYCYTES : LINES THE FLOOR OF THE
3RD VENTRICLE. THESE CELLS HAS LONG
BASAL PROCESSES. ITS END FEET IS
PLACED ON CAPILLARIES.
• CHOROIDAL EPITHELIAL CELLS : COVER
CHOROID PLEXUSES. THE BASE AND SIDE
OF CELLS ARE THROWN INTO FOLDS. HAS
TIGHT JUNCTIONS.

93. EPENDYMOCYTES LINES VENTRICLES OF BRAIN
AND SPINAL CORD.
HAS CILLIA AND MICROVILLI.
CILLIA HELPS IN THE
CIRCULATION OF THE CSF.
MICROVILLI HELPS IN THE
ABSORPTION OF CSF.

94. TANYCYTES
LINES THE FLOOR OF THE 3RD VENTRICLE. THESE ARE
SPECIALIZED EPENDYMAL CELLS. THESE CELLS HAS LONG
BASAL PROCESSES. IT’S END FEET IS PLACED ON CAPILLARIES.
TANYCYTES ARE INVOLVED IN TRANSPORT OF SUBSTANCES
FROM CSF TO BLOOD WITHIN THE PORTAL CIRCULATION OF
HYPOTHALAMUS. THEY ARE SENSITIVE TO GLUCOISE
CONCENTRATION.
SO THEY MAYBE INVOLVED IN DETECTING AND RESPONDING
TO CHANGES IN ENERGY BALANCE AS WELL AS MONITORING
OTHER CIRCULATING METABOLITES IN CSF. MAY CONTROL
HORMONE PRODUCTION FROM PITUTARY.

96. CHOROIDAL
EPITHELIAL CELLS :
COVER CHOROID
PLEXUSES. HELPS IN
THE PRODUCTION
OF CSF.

97. THE BASE AND SIDE
OF CELLS ARE
THROWN INTO
FOLDS. HAS TIGHT
JUNCTIONS.

98. BLOOD-CSF BARRIER
COMPONENTS OF BLOOD-CSF
BARRIER:
• FENESTRATED ENDOTHELIUM OF
CHOROID CAPILLARIES RESTING
ON A BASEMENT MEMBRANE.
• TISSUE SPACE B/W VASCULAR
ENDOTHELIUM AND PIA
MATTER.
• CONTINOUS LAYER OF
EPENDYMAL CELLS CONNECTED
BY JUNCTIONAL COMPLEXES.

99. BLOOD-CSF BARRIER
TOXIC WASTES ARE
ABSORBED FROM CSF
INTO THE CAPILLARIES.
FILTRATE CONTAINING
GLOUCOSE, OXYGEN ETC
ARE RELEASED INTO THE
CSF.

100. EPENDYMAL CELLS
FUNCTIONS
CHOROIDAL EPITHELIAL CELLS : HELPS
IN THE PRODUCTION AND SECRETION
OF CSF.
CILLIA IN EPENDYMOCYTES HELPS IN
CIRCULATION OF CSF.
MICROVILLI IN EPENDYMOCYTES HELPS
IN ABSORPTION OF CSF.
TANYCYTES ARE INVOLVED IN TRANSPORT OF SUBSTANCES FROM CSF TO BLOOD WITHIN THE PORTAL
CIRCULATION OF HYPOTHALAMUS. THEY ARE SENSITIVE TO GLUCOISE CONCENTRATION.
SO THEY MAYBE INVOLVED IN DETECTING AND RESPONDING TO CHANGES IN ENERGY BALANCE AS WELL AS
MONITORING OTHER CIRCULATING METABOLITES IN CSF. MAY CONTROL HORMONE PRODUCTION FROM
PITUTARY.
1
2
3

101. VENTRICULAR
SYSTEM

102. CIRCULATION
OF CSF

103. MICROGLIA
EMBRYOLOGICALLY NOT
RELATED TO OTHER
NEUROGLIAL CELLS. DERIVED
FROM MACROPHAGES
OUTSIDE THE NERVOUS
SYSTEM. THEY MIGRATE INTO
NERVOUS SYSTEM DURING
FETAL LIFE.
SMALLEST OF THE NEUROGLIA,
IS FOUND SCATTERED IN THE
CENTRAL NERVOUS SYSTEM.
THEY INCREASES IN NUMBER
IN CASE OF ANY INJURY,
DISEASES ETC

105. SATELLITE CELLS OF PNS THESE ARE A LAYER OF CUBOIDAL CELLS THAT
SURROUNDS NEURONAL CELL BODIES OF
GANGLIA.
THEY FORMS A COMPLETE LAYER AROUND THE
CELL BODY.
SATELLITE CELLS HELPS TO ESTABLISH & MAINTAIN
CONTROLLED MICROENVIORNMENT AROUND THE
NEURONAL BODY OF THE GANGLIA.
PROVIDE ELECTRICAL INSULATION & PATHWAY
FOR METABOLIC EXCHANGES – THUS
FUNCTIONALLY ANALOGOUS TO SCHWANN CELL
EXCEPT IT DOESN’T MAKE MYELIN.

106. SATELLITE CELL

107. CNS NEURONS, MACROGLIAL CELLS –
ASTROCYTES, OLIGODENDROCYTES &
EPENDYMAL CELLS : EMBRYONIC
NEUROECTODERM OF NEURAL TUBE.
PNS GANGLION CELLS AND PERIPHERAL GLIA
– NEURAL CREST.
MICROGLIA : MESODERM
EMBRYOLOGICAL
ORIGINS

108. ENTERIC
NEUROGLIA
MORPHOLOGICALLY AND FUNCTIONALLY
SIMILAR TO ASTROCYTES. THEY RESIDES
WITHIN THE WALL OF THE INTESTINAL
TRACT. REGULATES GASTROINTESTINAL
MOTILITY.

110. CONNECTIVE TISSUE OF A
PERIPHERAL NERVE

112. ENDONEURIUM
THESE ARE INTRA-FASCICULAR CONNECTIVE TISSUE.
THIS CONNECTIVE TISSUE CONSIST OF TYPE 1 COLLAGEN. ORGANANIZED IN
FINE BUNDLES LYING PARALLEL TO THE LONG AXIS OF NERVE AND
CONDENSED AROUND SCHWANN CELL AXON UNIT.
FIBROUS AND CELLULAR COMPONENT IS BATHED IN ENDONEURIAL FLUID
WHICH HAS HIGHER PRESSURE THAT EPINEURIUM.
CELLULAR COMPONENTS ARE SCHWANN CELLS, ASSOCIATED AXON,
ENDOTHELIAL CELLS, FIBROBLAST, MACROPHAGES & MAST CELLS.

113. PERINEURIUM
IT EXTENDS FROM CNS-PNS TRANSITION ZONE TO THE PERIPHERY.
CONSIST OF ALTERNATING LAYERS OF FLATTENED POLYGONAL
CELLS DERIVED FROM FIBROBLASTS & FIBERS. 15-20 LAYERS
PRESENT. TIGHT JUNCTIONS ARE PRESENT.
THIS FEATURE ACTS AS METABOLICALLY ACTIVE DIFFUSION
BARRIER. BLOOD-NERVE BARRIER. MAINTAINS OSMOTIC & FLUID
PRESSURE.

116. EPINEURIUM
IT IS THE CONDENSATION OF LOOSE AREOLAR TISSUE.
MORE FASCICULI PRESENT IN A PERIPHERAL NERVE – THICKER
THE EPINEURIUM.
EPINEURIUM CONTAIN FIBROBLASTS, COLLAGEN TYPE 1 & 3, FAT,
LYMPHATICS AND VASA NERVORUM.

131. GANGLIA
GANGLIA ARE THE AGGTEGATION
OF NEURONAL CELLBODIES.
THEY CAN BE FOUND IN
1. DORSAL ROOTS OF SPINAL
NERVE.
2. SENSORY ROOTS OF
TRIGEMINAL, FACIAL,
GLOSSOPHARYNGEAL, VAGAL
ND VESTIBULOCOCHLEAR
CRANIAL NERVES.
3. IN AUTONOMIC NERVES
4. ENTERIC NERVOUS SYSTEM

133. Sympathetic ganglion

134. Spinal ganglion

135. ECCENTRIC
NUCLEUS

140. CLINICAL ASPECT – NERVOUS
TISSUE

141. DEMYLENATION :
LOSS OF MYLEIN
SHEATH

142. CAUSES

150. AFFECTS POST-SYNAPTIC
NEUROMUSCULAR
JUNCTION

151. PERIPHERAL NERVE INJURY
CLASSIFICATIONS : SEDDON &
SUNDERLAND

153. PERIPHERAL
NERVE
REGENERATION

154. FREY’S SYNDROME :
ABNORMAL NEURON
REGENERATION

155. FREY’S SYNDROME
IN PENETRATING WOUND OF PAROTID
GLAND OR PAROTID GLAND SURGERY,
AURICULOTEMPORAL & GREAT AURICULAR
NERVES CAN GET DAMAGED. DURING
HEALING PROCESS, THE SECRETOMOTOR
FIBERS OF AURICULOTEMPORAL NERVE
GROWS OUT & JOIN WITH THE DISTAL END
OF THE GREAT AURICULAR NERVE.
THROUH WHICH THE FIBERS REACH THE
SWEAT GLAND IN THE FACIAL SKIN.
AS A RESULT, WHEN THE PATIENT EATS,
SWEATING CAN OCCUR OVER THE SKIN
COVERING THE PAROTID GLAND.

156. What is Wallerian Degeneration?
When there’s a cut to an axon, the axon neuron cell body becomes separate to the axon distal.
Therefore, the process of Wallerian degeneration is when this separated axon degenerates away from the site
of the injury. After the lesion happens, the axon tends to degenerate within 24-36 hours – but prior to this, the
distal axon may still be electrically excitable.

157. NERVE
TRANSPLANTATION

158. IVDP –
INTRAVERTEBRAL
DISC PROLAPSE.

159. IVDP SYMPTOMS:
PAIN & PARESTHESIA

160. HERPES ZOSTER : CHICKEN POX VIRUS - varicella zoster
virus CAN LAY DORMANT IN DORSAL ROOT GANGLION FOR
YEARS AND CAN BE ACTIVE IN LATER YEARS TO FORM HERPES
ZOSTER

162. POLIO AFFECTS ANTERIOR HORN
CELLS OF SPINAL CORD

166. BLACK FUNGUS / Mucormycosis
is a devastating opportunistic
infection associated with high
mortality. Most of the cases occur in
patients with uncontrolled diabetes
mellitus and compromised immune
status – AIDS, COVID -19 ETC. Rhino-
cerebral mucormycosis is the most
common form of the disease. The
fungus rapidly spreads from paranasal
sinuses to orbits and cavernous
sinuses with extension to intracranial
vasculature and brain. Common
pathological hallmark is vascular
invasion and neurotropism. One of
rhino-cerebral mucormycosis
complication is optic nerve
infarction.

169. GLIOSIS / REPLACEMENT
GLIOSIS : SCAR TISSUE
FORMATION AT THE SITE OF
NEURONAL DEATH. FOWING THE
DEATH OF NEURON DUE TO
CEREBROVASCULAR ACCIDENT /
STROKE OR ANY TRAUMA ETC
ASTROCYTES PROLIFERATES AND
FILL IN THE SPACE PREVIOUSLY
OCCUPIED BY NEURONS.

170. GLIOSIS

171. Neuroblastomas are
cancers that start in early nerve
cells (called neuroblasts) of the
sympathetic nervous system,
so they can be found anywhere
along this system.
• Most neuroblastomas begin
in sympathetic nerve ganglia
in the abdomen, about half
of these start in the adrenal
gland.
• Most of the rest start in
sympathetic ganglia near the
spine in the chest or neck, or
in the pelvis.

172. TUMOURS OF NEUROGLIA ACCOUNTS 40% - 50% OF INTRACRANIAL
TUMOURS. SUCH TUMOURS AS CALLED GLIOMAS. TUMOURS OF
ASTROCYTES ARE MOST COMMON. ASTROCYTOMA & GLIOBLASTOMA.

173. Ependymal cell tumor ..
Arise from the lining
epithelium of ventricles.

174. SCHWANNOMA – TUMOUR ARISING
FROM SCHWANN CELLS IN PNS

175. Trigeminal Schwannoma
AFFECTING TRIGEMINAL NERVE.

176. BRAIN TUMOUR CAN CAUSE PRESSURE SYMPTOMS & MIDLINE SHIFT
NORMAL

177. VARIOUS TYPES OF BRAIN HERNIATIONS BRAIN TUMOURS CAN CAUSE HERNIATIONS

178. THANK YOU