Lecture 8 - Nerve Tissue Histology

Question 1

3 main categories of neurons

Answer 1

Sensory neurons
Motor neurons
Interneurons or intercalated neurons

Question 2

have one axon and two or more dendrites .The direction of impulse is from dendrite to cell body to axon or from cell body to axon . Functionally cell body and dendrites are impulse generators and axon is for impulse conduction. Motor neurons and interneurons are the examples of multipolar neurons.

Answer 2

Multipolar neurons

Question 3

have one axon and one dendrite .They are found in receptors for special senses most commonly in retina of the eye and the ganglia for vestibulocochlear nerve in the ear.

Answer 3

Bipolar neurons

Question 4

have one process, the axon that divides close to the body into two long axonal branches. The examples are the sensory neurons located close to the CNS in the dorsal root ganglia and cranial nerve ganglia

Answer 4

Pseudo unipolar neurons

Question 5

Each stack of rough endoplasmic reticulum stains intensely with basophilic dyes and is called Nissl bodies.

Answer 5

Nissl bodies

Question 6

Neurons have one axon originating from the soma at the axon hillock and ending at ________

Answer 6

Telodendron

Question 7

In the CNS , functionally and structurally related neurons form aggregates called

Answer 7

Nuclei

Question 8

Clusters of neurons arranged in a layer form a _______or _______

Answer 8

stratum, lamina (cerebral cortex

Question 9

When neurons form longitudinal groups , these are called

Answer 9

Columns

Question 10

Bundles of axons in the CNS are ____ _____ ______

Answer 10

Tracts, fasculi, or lemnisci e.g. optic tract

Question 11

In the PNS , a cluster of neuron is called

Answer 11

Ganglion

Question 12

What system include these neuroglia
Schwann cells , satellite cells and certain cells in the motor end plate, retina and certain ganglia located in the alimentary canal.

Answer 12

Peripheral nervous system

Question 13

What system includes these neuroglia
 Astrocytes
Oligodendrocytes 
Microglia
Ependymal cells

Answer 13

Central Nervous sytem

Question 14

These produce myelin sheath that surrounds the axons and ensures rapid conduction of nerve impulses.

Answer 14

Schwann cells

Question 15

Are largest of the glial cells, closely associated with neurons and provide them support and modulate their activities .
They possess glial fibrillary acidic proteins ( GFAP) .Antibodies to GFAP are used as specific stains to identify astrocytes .
They play an important role in the movement of substances and waste to and from the neuron .They help to maintain tight junctions of the capillaries that form the blood brain barrier

Answer 15

Astrocytes

Question 16

Produce and maintain the myelin sheath of CNS .

Abnormalities of myelin synthesis is important in the pathogenesis of several autoimmune demyelinating diseases of CNS

Answer 16

Oligodendrocytes

Question 17

are phagocytic cells .
~5% of all glial cells of CNS , but proliferate and become actively phagocytic in regions of injury and disease . (reactive microglial cells )

Answer 17

Microglia

Question 18

Form epithelial like lining of the ventricles of the brain and spinal cord .These are cuboidal to low columnar cells that are tightly bound by junctional complexes

Answer 18

Ependymal cells

Question 19

These fascicles are enclosed by a thick connective tissue sheath called ________

Answer 19

Epineurium

Question 20

Each fascicle within the epineurium is surrounded by a _________, consisting of an outer layer connective tissue layer and an inner layer of flattened epitheloid cells

Answer 20

Perimeurium

Question 21

Each nerve fiber with its associated Schwann cell has its own slender connective tissue sheath , the _________ composed of collagenous and reticular fibers with fibroblasts and macrophages.

Answer 21

Endoneurium

Question 22

scar formation in CNS known as

Answer 22

Reactive gliosis

Question 23

Which heals better, CNS or PNS?

Answer 23

PNS