Chapter 12

Question 1

Neuroglia of CNS

Answer 1

oligodendrocytes, 
ependymal cells, 
Microgila
Astrocytes
Neuroglia
Astrocytes

Question 2

Neuroglia of the PNS

Answer 2

Schwann Cell

Satellite cell

Question 3

Oligodendrocytes

Answer 3

Form myelin sheath in brain and spinal cord.

Question 4

Ependymal cells

Answer 4

Lines the brain and spinal cord, secretes and circulates CSF

Question 5

Microgila

Answer 5

Phagoctize that destroy microorganisms, foreign matter and dead nervous tissue

Question 6

Astrocytes

Answer 6

1. Cover the brain surface and non synaptic regions of neurons
2. From supportive framework in CNS
3. Induce formation of blood brain barrier
4. Nourish neurons
5. Produce growth factors that stimulate neurons
6. Communicate electrically with neurons and may influence synaptic signaling.
7. Remove K+ and some neurotransmitters fro ECF of the brain and spinal cord
8. Help to regulate composition of ECF from scar tissue to replace damaged nervous tissue.

Question 7

Neuroglia of PNS

Answer 7

1. Schwann Cells

2. Satellite Cells

Question 8

Schwann Cells

Answer 8

Form neurilemma around all PNS nerve fiber and myelin around most of them; aid in generation of damaged nerve fibers.

Question 9

Satellite cells

Answer 9

Surrounding somas of the neuron in the ganglia; provide electrical insulation and regulates chemical environment of neurons

Question 10

Local Potential

Answer 10

Produced by gated channels on the dendrites and soma

Question 11

Action Potential

Answer 11

Produced by voltage-gated channels on the trigger zone and axon.

Question 12

Action Potential

Answer 12

Always begins with depolarization

Question 13

Action Potential

Answer 13

All or non; either does not occur at all or exhibits the same peak voltage regardless of stimulus or strength.

Question 14

Local Potential

Answer 14

May be a positive (depolarizing) or negative (hyperpolerizing) voltage charge Graded proportional to strength.

Question 15

Action Potential

Answer 15

Irreversible, goes to completion once it begins

Question 16

Local Potential

Answer 16

Reversible; returns to RMP if stimulation ceases before threshold is reached

Question 17

Local Potential

Answer 17

Has effects for only a short distance from point of origin.

Question 18

Local Potential

Answer 18

Decremental signal grows weaker with distance

Question 19

Action Potential

Answer 19

Self-propagating; has effects a great distance from point of origin

Question 20

Action Potential

Answer 20

Nondecremental’ signal maintains same strength regardless of its distance

Question 21

Acetylcholine ACh

Answer 21

Neuromuscular junctions, most synapses of autonomic nervous system, retina, and many parts of the brain, excites skeletal muscle, inhibits cardiac muscles, and has excitatory or inhibitory effects on smooth muscle and glands depending on location