Question 1

Which of the following best explains why the inside of a neuron is negatively charged relative to the outside at rest?

Accepted Answer

The sodium-potassium pump moves more positive charges out than in, and potassium ions leak out more easily than sodium ions leak in.

Question 2

A patient is given a drug that blocks voltage-gated sodium channels in neurons. Which of the following effects would most likely be observed?

Accepted Answer

Action potentials would fail to initiate or propagate.

Question 3

Which of the following is a direct result of the efflux of potassium ions during the repolarization phase of an action potential?

Accepted Answer

The membrane potential returns toward the resting value.

Question 4

Which of the following best describes the 'all-or-none' principle of action potentials?

Accepted Answer

Once threshold is reached, an action potential of fixed size occurs; if not, no action potential occurs.

Question 5

A person touches a hot stove and immediately withdraws their hand. Which type of receptor is primarily responsible for detecting the heat and pain?

Accepted Answer

Free nerve endings

Question 6

During the relative refractory period of a neuron, which of the following is true?

Accepted Answer

A stronger-than-normal stimulus is required to trigger an action potential.

Question 7

Which of the following best explains why the resting membrane potential is typically around -70 mV in neurons?

Accepted Answer

The membrane is more permeable to potassium ions, which leak out, and the sodium-potassium pump maintains ion gradients.

Question 8

Which of the following is an example of a cell that can spontaneously generate action potentials without external stimulation?

Accepted Answer

Pacemaker cells in the heart

Question 9

A patient experiences pain in their left arm during a heart attack. This is an example of:

Accepted Answer

Referred pain

Question 10

Which of the following best describes the function of osmoreceptors?

Accepted Answer

Detecting changes in osmotic pressure or solute concentration

Question 11

Which of the following scenarios best illustrates the concept of graded potentials?

Accepted Answer

A small stimulus causes a small depolarization, and multiple small stimuli can add together to reach threshold.

Question 12

Which of the following statements about the somatosensory cortex is correct?

Accepted Answer

It allocates more space to regions with higher sensory input, such as the hands and face.

Question 13

A researcher observes that a certain receptor continues to respond to a constant stimulus over time, such as the eye adapting to light. This receptor is most likely a:

Accepted Answer

Tonic receptor

Question 14

Which of the following best describes the role of endothelial cells in the nervous system?

Accepted Answer

They line blood vessels and help maintain the blood-brain barrier.

Question 15

Which of the following cranial nerve types is responsible for transmitting only sensory information to the brain?

Accepted Answer

Purely sensory cranial nerve

Question 16

A neuron is exposed to a toxin that keeps potassium channels open longer than normal after an action potential. What is the most likely effect on the membrane potential?

Accepted Answer

The membrane potential will become more negative than the resting potential (hyperpolarization).

Question 17

Which of the following best explains why the sodium-potassium pump is essential for neural signaling?

Accepted Answer

It maintains the ion gradients necessary for the generation of action potentials.

Question 18

Which of the following is most likely to occur if the cell membrane suddenly becomes equally permeable to sodium and potassium ions?

Accepted Answer

The resting membrane potential would approach zero (become less negative).

Question 19

A person is dehydrated and experiences intense thirst. Which neural structure is primarily responsible for detecting this change and initiating the thirst response?

Accepted Answer

Osmoreceptors in the hypothalamus

Question 20

Which of the following best illustrates the integration of chemistry and biology in the context of neural signaling?

Accepted Answer

The sodium-potassium pump uses ATP to maintain ion gradients, enabling action potentials in neurons.

Resting Membrane Potential and Neural Signaling: Key Concepts for General Chemistry and Biology

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