Wk 2 Nervous Tissue

Question 1

Glial cells in PNS

Answer 1

• Schwann cells

- satellite cells

Question 2

Glial cells in CNS

Answer 2

• oligodendrocytes
• astrocytes
• microglial cells
• ependymal cells

Question 3

Neural tube gives rise to what mature neural structures

Answer 3

neurons and glia of CNS

Question 4

Neural crest gives rise to what mature neural structures

Answer 4

sensory neurons of spinal and cranial ganglia, motor neurons of autonomic ganglia, glia of PNS, other non-neuronal cell types

Question 5

Gray matter

Answer 5

cell bodies

Question 6

White matter

Answer 6

myelinated axons

Question 7

Neuropil

Answer 7

packing material between/among cell bodies in CNS

Question 8

Neurofilaments

Answer 8

intermediate filaments in neurons

Question 9

Lipofucin

Answer 9

wear and tear pigments

Question 10

Nissl bodies

Answer 10

clumps of RER around cytoplasm

Question 11

Axon diameter notes

Answer 11

same diameter for entire length

Question 12

2 axon structures found before myelin sheath begins

Answer 12

axon hillock

initial segment

Question 13

Dense projections are thicker in presynaptic/postsynaptic neurons

Answer 13

presynaptic

Question 14

Kinesins vs dyneins

Answer 14

kinesins move materials down axon (faster)

dyeneins move materials up axon (slower)

Question 15

What are the + and - ends of microtubules?

Answer 15

+ ends are distal

Question 16

Astrocyte functions

Answer 16

• induce endothelial tight junctions

- pervasive, end in terminal feet

Question 17

Oligodendrocyte funcitons

Answer 17

myelinate CNS axons

Question 18

Microglia functions

Answer 18

phagocytic cells, differentiated monocytes

Question 19

Ependymal cells functions

Answer 19

• line central canal of cord and ventricles of brain
• ciliated simple cuboidal/columnar epithelium
• cilia beat and move CSF

Question 20

3 layers of CT covering peripheral nerves

Answer 20

epineurium-covers complete nerve
perineurium-covers facicles of nerve fibers
endoneurium-covers individual nerve fibers

Question 21

Schwann cells and unmyelinated fibers, what’s the deal?

Answer 21

neurolemma of Schwann cells covers unmyelinated fibers (no myelin present)

Question 22

Where are unmyelinated fibers found?

Answer 22

postganglionic autonomic neurons

Question 23

Schmidt-Lantermann clefts

Answer 23

missing myelin sheath in otherwise myelinated fiber

Question 24

Intraperiod line

Answer 24

layer of myelin sheath with cytoplasm

Question 25

Major dense line

Answer 25

layer of myelin sheath w/o cytoplasm

Question 26

What type of nuclei are found in postganglionic neurons

Answer 26

eccentric (off center)

Question 27

What types of nerve fibers are myelinated

Answer 27

A and B

Question 28

What types of nerve fibers are unmyelinated

Answer 28

C

Question 29

What is the function of satellite cells

Answer 29

form incomplete covering around neuronal cell bodies

Question 30

Wallerian (orthograde) degradation characteristics

Answer 30

- Schwann cells + CT remain --> hollow tube | - phagocytosis of debris

Question 31

Retrograde degradation

Answer 31

- degeneration of axon and myelin sheath in direction of cell body - cell death possible

Question 32

Chromatolysis

Answer 32

Nissl body dissolution

Question 33

Where is neuronal regeneration possible?

Answer 33

only PNS, oligodendrocytes do not leave hollow tubes

Question 34

Traumatic neuroma

Answer 34

heterogeneous mass of entangled large nerve fibers, Schwann cells, CT cells