Becker Exam I

Question 1

oligodendrocytes
location:
function:

Answer 1

CNS
myelinate axons in the CNS & uptake neurotransmittes

Question 2

astrocytes
location:
function:

Answer 2

CNS
maintain NT concentration, contribute to BBB tight junctions, borders brain surface, create scares, information network

Question 3

microglia
location:
function:

Answer 3

CNS
immune cell of CNS, active/phagocytize/APC

Question 4

Ependymal cells
location:
function:

Answer 4

CNS
lines ventricles, choroid plexus, and central canal of spinal cord
- simple cuboidal cilia = ventricles
- simple cuboidal no cilia = choroid plexus
- simple columnar = central canal

Question 5

schwann cells
location:
function:

Answer 5

PNS
myelinate axons in the PNS & support unmyelinated axons

Question 6

satellite cells
location:
function:

Answer 6

PNS
surround neuronal cell bodies

Question 7

4 functional zones of neurons

Answer 7

dendritic zone
cell body/soma
axonic zone
telodendritic zone

Question 8

3 types of neurons

Answer 8

bipolar
pseudounipolar
multipolar

Question 9

Define the differences between bipolar, pseudounipolar, and multipolar neurons and where they are each typically found in the body.

Answer 9

bipolar - sensory, special senses

pseudo unipolar - sensory, cranial, and spinal sensory ganglion

multipolar - most neurons, eccentric nucleus

Question 10

Describe what zone of a neuron contains signal receptors and the three different types of receptors classified by location.

Answer 10

dendritic zone
exteroceptors: external stimuli (vision, auditory, olfaction, taste, skin)
interoceptors: viscera, internal stimuli
proprioceptors: tendon organs & neuromuscular spindles

Question 11

Explain the differences in how oligodendrocytes achieve myelination as compared to neurolemma (Schwann) cells and where each cell type is located in the body.

Answer 11

Schwann cells (PNS) myelinate one segment of one axon

oligodendrocyte (CNS) myelinates several axon segments

Question 12

Describe saltatory conduction and identify nodes and internodes.

Answer 12

Saltatory conduction: speeds the conduction of the action potential

Question 13

Explain how myelination and axon diameter effects the conduction velocity of the action potential.

Answer 13

Increase in diameter = decreased resistance = increase in velocity

Increase in myelination = increase in conduction velocity

Question 14

difference between small-diameter axons and large-diameter axons in terms of conduction velocity

Answer 14

small diameter = slow, unmyelinated, pain

large diameter = fast, myelinated, proproception

Question 15

parts of NMJ

Answer 15

telodendria
synaptic cleft
motor end plate

Question 16

define motor unit

Answer 16

motor neuron + axon + NMJ + all the fibers it innervates

Question 17

white matter

Answer 17

glial cells & myelinated axons fiber tracts

Question 18

gray matter

Answer 18

neuronal cell bodies, dendrites, initital segment of axons (unmyelinated), glial cells, synapses

Question 19

neuropil

Answer 19

network of axons, dendrites, neuroglial and synapses

Question 20

Identify and describe the flow of signaling in the gray matter layers of the cerebellum.

Answer 20

granular layer –> molecular layer –> purkinje layer

Question 21

Describe the composition of the blood-brain-barrier.

Answer 21

endothelial tight junctions
continuous basement membrane
astrocytic end feet on blood vessels

Question 22

Define a nucleus in relation to the brainstem’s organization.

Answer 22

functional clusters of neuron cell bodies in the brainstem

Question 23

Explain the composition and function of the choroid plexus.

Answer 23

Composition: cuboidal ependymal cells with microvilli, fenestrated capillaries, c.t.
Function: Produces CSF

Question 24

sensory ganglion

Answer 24

receive signals from PNS –> CNS
central nucleus
more satellite cells
psuedounipolar neurons
no synpases
dorsal root ganglia & cranial ganglia
Cr.n. II and VII

Question 25

motor ganglion

Answer 25

eccentric nucleus
less satellite cells
multipolar neurons
many synapses
sympathetic & parasymp ANS
myenteric plexus ENS

Question 26

3 layers of c.t. are found in a peripheral nerve

Answer 26

epineurium
perineurium
endoneurium