Lecture 7: Nervous System

Question 1

If the permeability of a resting axon to sodium ion increases, then:

a. inward movement of sodium will increase and the membrane will depolarize.
b. the membrane potential will hyperpolarize.
c. inward movement of sodium ion will increase.
d. outward movement of sodium ion will decrease.

Answer 1

a. inward movement of sodium will increase and the membrane will depolarize.

Question 2

Drugs that have effects similar to those of sympathetic activation are called sympathomimetic drugs. Which of the following would you NOT expect to observe in a person who has taken a sympathomimetic drug? Find the FALSE answer.

a. sweating
b. increased heart rate
c. dilation of respiratory passages
d. decreased blood pressure

Answer 2

d. decreased blood pressure

Question 3

The cells that cover the outer surfaces of CNS capillary endothelial cells are the:

a. blastocytes.
b. astrocytes.
c. monocytes.
d. leukocytes.

Answer 3

b. astrocytes.

Question 4

The layer of the meninges that closely follows every gyrus and sulcus is the:

a. pia mater.
b. dura mater.
c. arachnoid membrane.
d. neural cortex.

Answer 4

a. pia mater.

Question 5

The white matter of the spinal cord contains:

a. bundles of axons with common origins, destinations, and functions.
b. bundles of dendrites with common origins, destinations, and functions.
c. sensory and motor nuclei.
d. both axons and dendrites.

Answer 5

a. bundles of axons with common origins, destinations, and functions.

Question 6

Many medications introduced into the bloodstream cannot directly affect the neurons of the CNS because:

a. oligodendrocytes form a continuous myelin sheath around the axons.
b. the endothelium of CNS capillaries forms a blood-brain barrier.
c. the neurolemma is impermeable to most molecules.
d. astrocytes form a capsule around neurons.

Answer 6

b. the endothelium of CNS capillaries forms a blood-brain barrier.

Question 7

Grace contracts a viral disease that destroys cells in the posterior gray horns in her spinal cord. As a result, which of the following would you expect?

a. loss of sensation in her torso
b. inability to breathe
c. problems with moving her arms
d. uncontrollable sweating of her feet

Answer 7

a. loss of sensation in her torso

Question 8

A patient has a stroke and heals. What type of glial cell accumulates within the damaged brain region creating a glial scar?

a. Schwann cells
b. satellite cells
c. oligodendrocytes
d. astrocytes

Answer 8

d. astrocytes*

Though I think oligodendrocytes is also a correct answer because of this sentence in our notes: CNS regeneration is minimal because astrocytes and oligodendrocytes inhibit regeneration (ie. glial scars).

Question 9

Wound healing does not proceed in the CNS as in the PNS because:

a. Astrocytes secrete anti-inflammatory molecules
b. Macrophages cannot clear debris as quickly in the CNS
c. There is no myelin for the neurons to follow
d. A and B only

Answer 9

d. A and B only

Question 10

If the sodium-potassium pumps in the plasma membrane fail to function, all of the following occur EXCEPT. Choose the FALSE answer.

a. the intracellular concentration of potassium ions will increase.
b. the neuron will slowly depolarize.
c. the membrane will slowly lose its capacity to generate action potentials.
d. the inside of the membrane will have a resting potential that is more positive than normal.

Answer 10

a. the intracellular concentration of potassium ions will increase.