Exam 5 Flashcards
1
Q
- True or false? Neurons make up most of the cells in the nervous system.
True
False
A
False
2
Q
2. Sensory neurons carry impulses \_\_\_\_\_ the central nervous system, while motor neurons carry impulses \_\_\_\_\_ the central nervous system. away from; toward along; through toward; away from between; toward
A
toward; away from
3
Q
3. An effector is \_\_\_\_\_. something that causes an effect a muscle or gland what a motor neuron stimulates all of the above
A
all of the above
4
Q
4. Which of the following carry impulses toward the cell body of a neuron? Axons Dendrites Glial cells Schwann cells
A
Dendrites
5
Q
- Which of the following is a function of the myelin sheath?
Increases the rate of conduction of a nerve impulse
Moves sodium and potassium ions by active transport
Protects the dendrites of motor neurons
All of the above
A
Increases the rate of conduction of a nerve impulse
6
Q
- Multiple sclerosis results from which of these?
The destruction of the myelin sheath that surrounds axons in the CNS
The inhibition of the ion channels crossing the cell membrane
The underproduction of neurotransmitters
The failure of motor neurons to carry information
A
The destruction of the myelin sheath that surrounds axons in the CNS
7
Q
7. Ion channels are \_\_\_\_\_ in the plasma membrane that allow \_\_\_\_\_ to pass through. glycoproteins; ions phospholipids; cholesterol ions; proteins proteins; ions
A
proteins; ions
8
Q
8. The resting potential of a neuron is maintained by \_\_\_\_\_. the myelin sheath acetylcholine the sodium-potassium pumps neuroglial cells
A
the sodium-potassium pumps
9
Q
- A neuron was stimulated with 0.075 volts, and no action potential occurred. Later, it was stimulated with 0.15 volts, and it fired an action potential. What conclusions can you draw from this?
Acetylcholinesterase levels were too high.
The action potential threshold must be between 0.075 V and 0.15 V.
Both of these stimuli are too weak to produce an action potential.
All of the above
A
The action potential threshold must be between 0.075 V and 0.15 V.
10
Q
- True or false? Action potentials can be small, medium, or large in size (and any size in between).
True
False
A
False
11
Q
- Diffusion of calcium into the synaptic knob of a presynaptic neuron generates which immediate response?
Deactivation of neurotransmitters by enzymes in the synaptic cleft
Absorption of neurotransmitters by the postsynaptic neuron
Repolarization of the postsynaptic neuron
Fusion of synaptic vesicles with the neuron’s plasma membrane and release of neurotransmitter
A
Fusion of synaptic vesicles with the neuron’s plasma membrane and release of neurotransmitter
12
Q
12. Nerve impulses cannot reverse and travel up the axon toward the cell body due to \_\_\_\_\_. the refractory period the resting potential the action potential summation
A
the refractory period
13
Q
- During an action potential, repolarization occurs _____.
when sodium diffuses into the cell
when potassium diffuses out of the cell
when calcium ions diffuse into the synaptic knob
only where sodium-potassium pumps are absent
A
when potassium diffuses out of the cell
14
Q
14. The effect of a given transmitter within a synapse is determined by the \_\_\_\_\_. type of neurotransmitter released amount of neurotransmitter released type of receptor number of Schwann cells on the axon
A
type of receptor
15
Q
15. Which of these is controlled by serotonin? Mood, hunger, thirst, and sex drive Emotions and complex movement Feeling of well-being All of these are controlled by serotonin
A
Feeling of well-being
