Question 1

Which of the following best describes the primary contributors to the resting membrane potential in neurons?

Accepted Answer

The sodium-potassium pump, selective permeability to potassium ions, and ion channel distribution.

Question 2

A patient is exposed to a toxin that prolongs the opening of chloride channels in their neurons. What is the most likely effect on their action potentials?

Accepted Answer

The neuron will become hyperpolarized, making it harder to generate action potentials.

Question 3

Which statement best explains the 'all-or-none' principle of action potentials?

Accepted Answer

Once threshold is reached, an action potential of fixed size is generated; sub-threshold stimuli do not produce action potentials.

Question 4

During the relative refractory period, which of the following is true about the neuron's ability to generate another action potential?

Accepted Answer

A stronger-than-normal stimulus is required to generate another action potential.

Question 5

Which of the following best describes the function of pacemaker cells in cardiac muscle?

Accepted Answer

They spontaneously generate action potentials that regulate the heartbeat.

Question 6

A patient has a mutation that causes their sodium-potassium pump to function at half its normal rate. What is the most likely effect on their resting membrane potential?

Accepted Answer

The resting membrane potential will become less negative (depolarized).

Question 7

Which of the following is a correct example of a graded potential?

Accepted Answer

A postsynaptic potential that varies in magnitude depending on the amount of neurotransmitter released.

Question 8

Which of the following best explains why free nerve endings are important in the skin?

Accepted Answer

They detect changes in temperature and pain.

Question 9

A person enters a dark room after being in bright sunlight. Which type of sensory receptor is primarily responsible for their increased sensitivity to light over time?

Accepted Answer

Tonic receptors

Question 10

Which of the following best describes the role of the primary sensory cortex in the brain?

Accepted Answer

It processes and interprets sensory information from the body.

Question 11

A patient is unable to feel pain in their left hand but can still move it normally. Which type of receptor or neural pathway is most likely affected?

Accepted Answer

Free nerve endings responsible for pain sensation

Question 12

Which of the following scenarios best illustrates the concept of a 'graded potential'?

Accepted Answer

A postsynaptic neuron receives varying amounts of neurotransmitter, resulting in different levels of depolarization.

Question 13

Which of the following is NOT a characteristic of the absolute refractory period?

Accepted Answer

A stronger stimulus can generate another action potential.

Question 14

Which of the following best explains why the brain allocates more space to the upper lip in the sensory cortex?

Accepted Answer

The upper lip has a higher density of sensory receptors, requiring more cortical area for processing.

Question 15

A person experiences chest pain that is also felt in their left arm. This is an example of:

Accepted Answer

Referred pain

Question 16

Which of the following best describes the function of tonic receptors?

Accepted Answer

They continue to respond to a stimulus as long as it is present, adapting slowly.

Question 17

Which of the following is a real-life example of the all-or-none principle in action?

Accepted Answer

A neuron fires an action potential only if the threshold is reached, regardless of how strong the stimulus is above threshold.

Question 18

Which of the following best explains why action potentials travel in only one direction along an axon?

Accepted Answer

The absolute refractory period prevents the action potential from re-initiating in the region just activated.

Question 19

A researcher records a membrane potential of $$-70 mV in a $$resting neuron. Which of the following changes would most likely depolarize the neuron?

Accepted Answer

Opening sodium channels to allow sodium influx.

Question 20

Which of the following best describes the function of pacemaker cells in the heart?

Accepted Answer

They generate action potentials spontaneously to regulate the heartbeat.

Resting Membrane Potential and Neural Signaling

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