Q: Which equation best represents the reversal of resting membrane potential during an action potential?

$$RMP: -70 \rightarrow +30\ \text{mV}$$

Question 1

Graded potentials are due to ________ moving across the membrane. Which of the following best describes the effect of cation influx on the membrane potential?

Accepted Answer

It causes depolarization, making the inside less negative.

Question 2

The principle way neurons communicate is through action potentials. Which of the following best describes the 'all-or-none' principle of action potentials?

Accepted Answer

Action potentials only occur if the stimulus is above threshold and do not decrease in amplitude with distance.

Question 3

During the sharp depolarization phase of an action potential, which ion is primarily responsible for the change in membrane potential?

Accepted Answer

Influx of sodium ($$Na^+)$$

Question 4

Which of the following best explains why action potentials are self-propagating?

Accepted Answer

Once initiated, the depolarization at one segment of the axon triggers the opening of sodium channels in the next segment.

Question 5

Conduction velocity of an action potential is most affected by which of the following?

Accepted Answer

The amount of myelination and the diameter of the axon.

Question 6

The refractory period is important because:

Accepted Answer

It prevents the backward propagation of the action potential.

Question 7

During the absolute refractory period, which of the following is true?

Accepted Answer

No second action potential can be generated, regardless of stimulus strength.

Question 8

Most neuronal synapses are axon to ________, but can also be axon to cell body or axon terminal.

Accepted Answer

dendrite

Question 9

At a chemical synapse, information is transferred in one direction. Which step occurs first?

Accepted Answer

Action potential arrives at the axon terminal.

Question 10

Which neurotransmitter is primarily involved in activating skeletal muscles and is decreased in Alzheimer's disease?

Accepted Answer

Acetylcholine

Question 11

Which neurotransmitter is involved in the 'fight-or-flight' response and is a stress/adrenaline hormone?

Accepted Answer

Norepinephrine

Question 12

Which neurotransmitter is associated with the brain's reward mechanism and controls motor movement, with decreased levels in Parkinson's disease?

Accepted Answer

Dopamine

Question 13

Which neurotransmitter is the main inhibitory neurotransmitter, often mimicked by sedative drugs?

Accepted Answer

GABA

Question 14

Excitatory post-synaptic potentials (EPSPs) ________ the chance to produce an action potential at the postsynaptic membrane.

Accepted Answer

increase

Question 15

Inhibitory post-synaptic potentials (IPSPs) ________ the chance to produce an action potential at the postsynaptic membrane.

Accepted Answer

decrease

Question 16

Which of the following best describes synaptic integration?

Accepted Answer

Multiple EPSPs can summate to reach threshold and cause the postsynaptic neuron to fire.

Question 17

Which equation best represents the reversal of resting membrane potential during an action potential?

Accepted Answer

$$RMP: -70 ightarrow +30\ 	ext{mV}$$

Question 18

Which of the following mechanisms is NOT a way neurotransmitters are removed from the synaptic cleft?

Accepted Answer

Active transport into the postsynaptic cell

Question 19

Which neurotransmitter is a natural opiate that inhibits pain signaling?

Accepted Answer

Endorphin

Question 20

Which neurotransmitter mediates pain signaling?

Accepted Answer

Substance P

Nerve Impulses: Graded Potentials, Action Potentials, and Synaptic Transmission Lecture 11.2 note

Guida di studio - Domande di pratica

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