histology of central nervous system dr. sama ul haque

Histologyof

Central Nervous System

Dr. Sama ul Haque

Objectives

Describe the microscopic anatomy of gray

matter & white matter

Describe the microscopic anatomy of neuroglial

cells of CNS

Describe the microscopic anatomy of spinal cord.

Discuss the microscopic anatomy of Cerebral

cortex.

Discuss the microscopic anatomy of Cerebellum.

Describe the microscopic anatomy Meninges

Gray matter & White matter

Gray matter

Contains abundant neuronal cell bodies, dendrites, the initial unmyelinated portions of axons, & neuroglial cells .

White matter Contains myelinated fibers & neuroglial

cells .

Neuroglial Cells of CNS

They are nonneuronal, supportive cells

4 types of cells can be seen:

1. Astrocyte

Form part blood-barrier

2 types:

fibrous astrocytes

protoplasmic astrocytes

2. Oligodendrocytes

Form myelin sheath around axons in the CNS

3. Microglia

Are small cells with complex shapes.

Phagocytotic cells.

4. Ependymal Cells

Line the ventricles of the brain and the central canal of

the spinal cord

low columnar cilated epithelial cells

Spinal Cord

Spinal Cord

Spinal Cord

(Motor Neurons) Spinal Cord

Gray Matter

I. Molecular Layer (Plexiform Layer):

Pia Mater and Neuroglial cells

II. External Granular layer:

Small pyramidal cells

III.External Pyramidal layer:

Medium-sized pyramidal cells

IV.Internal Granular layer (Ganglionic Layer):

Small granule cells

Cerebral Cortex

Gray Matter

V. Internal Pyramidal layer:

Largest pyramidal cells (Betz Cells)

VI. Multiform layer (Layer of polymorphic cells):

Fusiform cells

Granule cells

Stellate cells

Cells of Martinotti

Cerebral Cortex

White Matter

Bundles of Axons

Cerebral Cortex

Cerebral Cortex

Cerebral Cortex (Layer V)

T.S of Cerebellum

Gray Matter

I. Molecular Layer:

Stellate cells

Basket cells

Neuroglial cells

II. Purkinje cell layer:

Purkinje cells:

Flask shaped

Arranged in a single layer having Thick dendrites.

Cerebellum

Gray Matter

III. Granular layer:

Small Granule cells with dark stained nuclei

Golgi type II cells

Glomeruli

Cerebellum

Cerebellar Cortex

Meninges

Are connective tissue covering the brain &

spinal cord

Three meningial layers are distinguished:

1. Dura is thick external layer consisting of dense C.T

2. Arachanoid(arachnoeides, spiderweblike) has two components:

(1) Sheet of connective tissue in contact with the dura mater

(2) System of loosely arranged trabeculae containing fibroblasts and collagen.

3. Pia is a delicate & loose connective tissue containing

many blood vessels.

Thank You