Q: Which ions are primarily responsible for establishing the resting membrane potential, and where are they located?

Potassium ($$\text{K}^+) is $$higher inside the cell, sodium ($$\text{Na}^+) is $$higher outside the cell.

Q: Which event during the action potential is most responsible for re-establishing the resting membrane potential after depolarization?

Activation of voltage-gated potassium ($$\text{K}^+) $$channels allowing $$\text{K}^+ to $$exit the cell.

Q: What mechanism maintains the resting membrane potential in neurons, and how does it function?

The sodium-potassium pump ($$\text{Na}^+/\text{K}^+$$ ATPase) actively transports $$3\ \text{Na}^+$$ out and $$2\ \text{K}^+ in $$per ATP hydrolyzed.

Q: Which statement best describes the direction of ion flow during depolarization in an action potential?

Voltage-gated sodium ($$\text{Na}^+) $$channels open, allowing $$\text{Na}^+ to $$flow into the cell.

Q: Which ion channel is activated during repolarization, and what is its effect?

Voltage-gated potassium ($$\text{K}^+) $$channels open, allowing $$\text{K}^+ to $$exit the cell.

Question 1

Which of the following best describes the resting membrane potential (RMP) of a typical neuron?

Accepted Answer

It is the voltage difference across the plasma membrane when the cell is inactive, typically around $$-70\ 	ext{mV}.$$

Question 2

Which ions are primarily responsible for establishing the resting membrane potential, and where are they located?

Accepted Answer

Potassium ($$	ext{K}^+) is $$higher inside the cell, sodium ($$	ext{Na}^+) is $$higher outside the cell.

Question 3

Which event during the action potential is most responsible for re-establishing the resting membrane potential after depolarization?

Accepted Answer

Activation of voltage-gated potassium ($$	ext{K}^+) $$channels allowing $$	ext{K}^+ to $$exit the cell.

Question 4

What mechanism maintains the resting membrane potential in neurons, and how does it function?

Accepted Answer

The sodium-potassium pump ($$	ext{Na}^+/	ext{K}^+$$ ATPase) actively transports $$3\ 	ext{Na}^+$$ out and $$2\ 	ext{K}^+ in $$per ATP hydrolyzed.

Question 5

Which equation represents Ohm’s law as applied to membrane potentials?

Accepted Answer

$$V = I 	imes R$$

Question 6

Which type of ion channel is primarily involved in generating graded potentials, and what activates it?

Accepted Answer

Ligand-gated channels activated by neurotransmitter binding.

Question 7

Where do graded potentials typically occur in a neuron?

Accepted Answer

Dendrites and cell body (soma).

Question 8

During an action potential, what is the threshold value that must be reached to initiate depolarization?

Accepted Answer

$$-55\ 	ext{mV}$$

Question 9

Which statement best describes the direction of ion flow during depolarization in an action potential?

Accepted Answer

Voltage-gated sodium ($$	ext{Na}^+) $$channels open, allowing $$	ext{Na}^+ to $$flow into the cell.

Question 10

What is the maximum value reached during depolarization in a typical neuron action potential?

Accepted Answer

$$+30\ 	ext{mV}$$

Question 11

Which ion channel is activated during repolarization, and what is its effect?

Accepted Answer

Voltage-gated potassium ($$	ext{K}^+) $$channels open, allowing $$	ext{K}^+ to $$exit the cell.

Question 12

During hyperpolarization, what is the typical membrane potential reached?

Accepted Answer

$$-90\ 	ext{mV}$$

Question 13

Which statement best describes the all-or-none phenomenon of action potentials?

Accepted Answer

If threshold is reached, an action potential is generated; if not, no action potential occurs.

Question 14

How does the nervous system interpret the strength of a stimulus based on action potentials?

Accepted Answer

By the frequency of action potentials generated.

Question 15

Which of the following best describes the absolute refractory period?

Accepted Answer

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

Question 16

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

Accepted Answer

A stronger-than-normal stimulus can generate a new action potential.

Question 17

A patient is given a drug that increases the permeability of the neuronal membrane to sodium ($$	ext{Na}^+). $$What effect would this have on the resting membrane potential?

Accepted Answer

The resting membrane potential would become less negative (depolarize).

Question 18

If a neuron’s membrane resistance ($$R) $$decreases while the current ($$I) $$remains constant, what happens to the membrane potential ($$V) $$according to Ohm’s law?

Accepted Answer

Membrane potential decreases, since $$V = I 	imes R.$$

Question 19

A neuron receives simultaneous excitatory and inhibitory graded potentials. Which of the following best describes the outcome?

Accepted Answer

The graded potentials summate, and the net effect determines whether threshold is reached.

Study Guide for Membrane Potentials, Graded Potentials, and Action Potentials (Anatomy & Physiology)

Study Guide - Practice Questions

Study Guide - Flashcards