SM56_NervousSystemHistology

Question 1

Embryologic derivation of nervous tissue

Answer 1

ECTODERM (specifically neuroectoderm and neural crest)

Question 2

1) Loose connective tissue surrounding each individual neuron
2) Specialized connective tissue surrounding each nerve fascicle (neuron bundle)
3) Dense irregular connective tissue that surrounds a group of nerve fascicles and fills the space between nerve fascicles

Answer 2

endoneurium, perineurium, epineurium

Question 3

Neurons are specialized for 1) and 2)

Answer 3

nerve impulse conduction, high levels of protein production

Question 4

Nissl Bodies

Answer 4

stacks of rough ER present in cytoplasm of neuron responsible for protein production (stains to toluidene blue)

Question 5

Dendrites are distinguished from axons in that they have _________. Both axons and dendrites contain ______ and _______ for both anterograde and retrograde transport

Answer 5

free ribosomes; microtubules, neurofilaments

Question 6

Lipid-rich sheath that wraps around axons to increase speed of impulse transmission

Answer 6

myelin sheath

Question 7

T or F: although neurons do not divide, areas of the brain have neural stem cells that can differentiate to replace damaged nerve cells

Answer 7

T

Question 8

4 types of neurons based on morphology

Answer 8

unipolar, pseudounipolar, bipolar, multipolar

Question 9

General and visceral sensory neurons are ______

Answer 9

pseudounipolar

Question 10

Somatomotor, autonomic, and interneurons are _____

Answer 10

multipolar

Question 11

Types of glial cells in the CNS

Answer 11

Oligodendrocytes: surrounds neurons, produce myelin
Astrocytes: scaffolding in brain tissue, cell processes surround neuron processes and extend to blood vessel
Microglia: phagocytic, immunity
Ependymal: line ventricles and spinal canal to produce CSF

Question 12

T or F: a majority of tumors within the CNS are derived from neurons

Answer 12

F; a majority are derived from supporting cells of neurons (glial cells)

Question 13

The oligodendrocytes of the peripheral nervous system

Answer 13

Schwann Cells

Question 14

T or F: Schwann cells surround axons of both myelinated and unmyelinated axons

Answer 14

T - they produce the myelin sheath in myelinated nerves, and are “neurilemma” in the unmyelinated axon (thin layers of schwann cells wrapping axon)

Question 15

In the spinal cord, ______ _____ (cell bodies and supporting cells) form the inner substance and _____ ______ (myelinated nerve fibers) occupies the periphery

Answer 15

grey matter, white matter (this is reversed in the cerebral cortex, where grey matter is on the periphery and white matter inside)

Question 16

______ ______ is an autoimmune disease characterized by loss of myelin in neurons

Answer 16

multiple sclerosis

Question 17

Types of synapses (3)

Answer 17

axodendritic, axoaxonal, axosomatic (axon to cell body)

Question 18

Many of the nuclei seen in the histological cross section of a nerve are _______ cells

Answer 18

Schwann cells