DLA 25 + DLA 26 + lecture 35

Question 1

What are the two functional domains of the PNS?

Answer 1

somatic (voluntary) and visceral (involuntary)

Question 2

What makes up the PNS?

Answer 2

1. cranial nerves
2. spinal nerves
3. ganglia
4. enteric plexuses
5. sensory receptors

Question 3

Functions of the nervous system?

Answer 3

1. sensory function
2. integrative function
3. motor function

Question 4

What are motor efferent neurons?

Answer 4

conveys impulses to effector cells
somatic- muscle cells
visceral - cardiac muscle and glands
typically multipolar

Question 5

What are sensory afferent neurons?

Answer 5

conveys impulses from receptors for integration
somatic - pain, temp, touch, pressure, proprioception
visceral - distension, ischemia, inflammation, physiological processes

typically pseudounipolar or bipolar

Question 6

What are interneurons?

Answer 6

communication and integration between sensory and motor neurons, tendon reflexes

Question 7

what are the neuroglial cells in the CNS?

Answer 7

1. astrocyte
2. oligodendrocytes
3. microglia
4. ependymal cells

Question 8

What are the neuroglial cells in the PNS?

Answer 8

1. schwann cells

2. satellite cells

Question 9

collection of cell bodies in the CNS?

Answer 9

A nucleus

Question 10

collection of axons in the CNS?

Answer 10

A tract

Question 11

collection of cell bodies in the PNS?

Answer 11

ganglion

Question 12

collection of axons in the PNS?

Answer 12

peripheral nerve

Question 13

What are the characteristics of sensory ganglia?

Answer 13

central axons
large pale staining of central nuclei
no synaptic connections
groups of pseudounipolar cell bodies

Question 14

What are the characteristics of autonomic ganglia?

Answer 14

large cell bodies
random bundles of fibers
groups of multipolar cell bodies
synapsing

Question 15

explain fibrous astrocytes?

Answer 15

prevalent in white matter

straight processes

Question 16

Explain protoplasmic astrocytes?

Answer 16

prevalent in gray matter
branching cytoplasmic processes
maintain the BBB

Question 17

differences between schwann cells and oligodendrocytes?

Answer 17

oligo = CNS and can myelinate several axons

schwann = PNS and can myelinate one axon
clean up debris

Question 18

What do ependymal cells do?

Answer 18

they are cuboidal / columnar

fluid transporting / absorbing cells

found in choroid plexus

secrete CSF

Question 19

Explain satellite cells?

Answer 19

small cuboidal cells

surround the cell body of neurons in the PNS

regulate the perineuronal environment

regulate metabolic exchange

Question 20

explain the formation of myelin?

Answer 20

A schwann cell plasma membrane forms two
distinct polarized domains
-abaxonal plasma membrane
-adaxonal plasma membrane

The mesoaxon connects the abaxonal and
adaxonal membranes and closes off the
extracellular environment

Question 21

What protein/gene regulates the thickness of the myelin?

Answer 21

neuregulin (ngr-1)

Question 22

the types of cytoplasm found in the myelin sheath

Answer 22

Inner collar of Schwann cell cytoplasm- between axon and myelin

Schmidt-Lantermann clefts- small islands of cytoplasm within

lamellae of myelin

Perinodal cytoplasm at node of Ranvier

Outer collar of Schwann cell cytoplasm
- around myelin