Q: Which equation best represents the Nernst equation for calculating the equilibrium potential of an ion across a membrane?

$$E = \frac{RT}{zF} \ln \frac{[\text{ion outside}]}{[\text{ion inside}]}$$

Question 1

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

Accepted Answer

The sodium-potassium pump, ion channels, and selective permeability of the cell membrane

Question 2

A neuron is exposed to a stimulus that is just strong enough to reach threshold. Which principle explains why the neuron fires a full action potential rather than a partial one?

Accepted Answer

All-or-none principle

Question 3

During the absolute refractory period, which of the following is true regarding the generation of a new action potential?

Accepted Answer

No stimulus, regardless of strength, can generate a new action potential

Question 4

Which equation best represents the Nernst equation for calculating the equilibrium potential of an ion across a membrane?

Accepted Answer

$$E = \frac{RT}{zF} \ln \frac{[	ext{ion outside}]}{[	ext{ion inside}]}$$

Question 5

Which of the following best explains why graded potentials differ from action potentials?

Accepted Answer

Graded potentials vary in magnitude and can summate, while action potentials are all-or-none and do not summate

Question 6

A patient is unable to track moving objects with their eyes, but can still see stationary objects clearly. Which brain structure is most likely affected?

Accepted Answer

The superior colliculus

Question 7

Which of the following is a function of free nerve endings in the skin?

Accepted Answer

Detecting changes in temperature and pain

Question 8

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

Accepted Answer

They generate action potentials spontaneously without external input

Question 9

A person enters a dark room after being in bright sunlight. Which type of receptor is responsible for the heightened sensitivity to light that develops over time?

Accepted Answer

Tonic receptors

Question 10

Which of the following statements about the sodium-potassium pump is correct?

Accepted Answer

It moves three sodium ions out of the cell and two potassium ions into the cell per ATP hydrolyzed

Question 11

Which cranial nerve is purely sensory and responsible for the sense of smell?

Accepted Answer

Olfactory nerve

Question 12

Which of the following best describes the effect of hyperpolarization on a neuron?

Accepted Answer

It makes the membrane potential more negative, decreasing the likelihood of generating an action potential

Question 13

Which of the following is true regarding the relative refractory period?

Accepted Answer

A new action potential can be generated only if the stimulus is stronger than normal

Question 14

Which of the following best explains the concept of 'graded potentials'?

Accepted Answer

They can vary in amplitude depending on the strength of the stimulus

Question 15

Which of the following is a correct statement about the 'all-or-none' principle of action potentials?

Accepted Answer

Action potentials are always the same size once threshold is reached

Question 16

Which of the following best describes the function of the superior colliculus in the brain?

Accepted Answer

It coordinates eye movements, especially tracking moving objects

Question 17

Which of the following is a real-life example of referred pain?

Accepted Answer

Pain in the left arm during a heart attack

Question 18

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

Accepted Answer

They adapt quickly to a stimulus and stop firing if the stimulus remains constant

Question 19

Which of the following is true about the permeability of the neuronal membrane at rest?

Accepted Answer

It is more permeable to potassium ions than sodium ions

Question 20

A neuron receives multiple subthreshold graded potentials at the same time. What is the likely outcome?

Accepted Answer

The graded potentials may summate to reach threshold and trigger an action potential

Resting Membrane Potential and Neural Signaling

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