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Flashcards in Phys 46/47 Deck (23)
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1

Prolonged changes in neuronal activity are achieved through the activation of:
A. Voltage gated chloride channels
B. Transmitter gated sodium channels
C. G-protein coupled channels
D. Voltage gated potassium channels

C

2

In a neuron with a resting membrane potential of -65 mV, the distribution of which ion across the neuronal membrane represents the greatest potential electromotive force (EMF)?
A. Potassium
B. Chloride
C. Sodium
D. Calcium

C

3

Inhibition of neuronal activity can be achieved by:
A. Allowing calcium to enter the presynaptic membrane
B. Opening sodium channels
C. Opening sodium and chloride channels simultaneously
D. Opening postsynaptic calcium channels

C

4

Transmission of the electrical signal from the dendrites to the soma of a neuron occurs by:
A. Short circuit current flow
B. An action potential mechanism
C. Electrotonic conduction
D. Capacitive discharge

C

5

Post-tetanic facilitation is thought to be the result of:
A. Opening voltage-gated sodium channels
B. Opening transmitter gated potassium channels
C. A build up of calcium in the presynaptic terminal
D. Electrotonic conduction

C

6

Hypoventilation has which effect on neuronal activity?
A. Hypoventilation depress neuronal activity
B. Hypoventilation increases neuronal activity
C. Hypoventilation increases synaptic delay
D. Hypoventilation decreases neurotransmitter release

A

7

The opening of which of the following ion channels would have the least effect on the resting membrane potential of an average neuron?
A. Sodium
B. Potassium
C. Chloride
D. The opening of any of the above ion channels would effect the resting membrane potential to a similar degree

C

8

An excitatory postsynaptic potential (EPSP):
A. Results from the simultaneous opening of sodium and chloride channels
B. Results from the opening of potassium channels
C. Results from the opening of sodium channels
D. Results from the opening of calcium channels

C

9

An inhibitory postsynaptic potential (IPSP):
A. Results from the opening of potassium channels
B. Results from the opening of sodium channels
C. Results from the opening of voltage-gated sodium channels
D. Results from the opening of voltage-gated calcium channels

A

10

Which of the following statements best describes the role of calcium in the release of a neurotransmitter substance from the presynaptic nerve terminal?
A. Calcium entry into the presynaptic terminal prevents the release of the neurotransmitter
B. Calcium entry into the presynaptic terminal is necessary for the release of the neurotransmitter
C. Calcium induces the opening of calcium-dependant sodium channels on the presynaptic terminal
D. Calcium entry into the presynaptic terminal results in the formation of cAMP which induces a conformational change in the presynaptic sodium channel that leads to the release of neurotransmitter

B

11

Which of the following neurotransmitters is thought to be involved in the phenomenon of presynaptic inhibition?
A. GABA
B. Serotonin
C. Norepinephrine
D. Acetylcholine

A

12

Forced rapid breathing results in alkalization of the blood which would lead to which of the following changes in neuronal activity?
A. A decrease in neuronal activity
B. An increase in neuronal activity
C. An initial decrease followed by an increase
D. No change in neuronal activity

B

13

In a neuron with a resting membrane potential of -65 mV, the distribution of which ion across the neuronal membrane represents the least potential electromotive force (EMF)?
A. Potassium
B. Chloride
C. Sodium
D. Calcium

B

14

Which of the following represents a rapidly adapting receptor?
A. Muscle spindle receptor
B. Ruffini endings
C. Meissner’s corpuscle
D. Merkel discs

C

15

Which of the following statements best describes the receptor potential?
A. The receptor potential is always constant
B. The greater the intensity of the stimulus, the greater the change in receptor potential
C. Any change in the receptor potential will induce an action potential
D. Receptor excitation always involves depolarization of the receptor

B

16

Signal amplification can be achieved by which of the following neuronal pool schemes?
A. Divergence in the same tract
B. convergence from multiple sources
C. through lateral inhibition
D. through a reverberating circuit

A

17

Which of the following types of sensory nerve fibers has the fastest transmission rate for action potentials?
A. Type C
B. Type A-GAMMA
C. Type A-BETA
D. Type A-DELTA

C

18

In the various types of neuronal circuits, signal sharpening is achieved by which of the following?
A. A diverging circuit
B. A converging circuit
C. A reverberating circuit
D. A circuit with lateral inhibition

D

19

Which of the following types of sensory nerve fibers has the slowest rate of transmission nerve impulses?
A. Type C
B. Type A-GAMMA
C. Type A-BETA
D. Type A-DELTA

A

20

Which of the following represents a slowly adapting receptor?
A. Pacinian corpuscle
B. Semicircular canal receptor
C. Meissner’s corpuscle
D. Merkel discs

D

21

Which of the following types of neuronal circuits is self-stimulating once activated?
A. Converging
B. Reverberating
C. Diverging
D. One that incorporates lateral inhibition

B

22

Which of the following statements concerning the mechanoreceptive receptor potential are true?
A. An increase in stimulus energy results in an increase in receptor potential
B. When receptor potential rises above a certain threshold, action potentials will appear in the neuron attached to the receptor
C. The number of action potentials generated in the neuron attached to the receptor is proportional to the receptor potential
D. All of the above are correct

D

23

Which of the following is a characteristic of almost all sensory receptors?
A. The ability to perceive a mechanical force
B. The ability to be modulated by a change in temperature
C. The ability to be excited by the application of a chemical irritant
D. The ability to adapt to the stimulus

D