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 3 sodium ions out and 2 potassium ions in, creating a net negative charge inside.

Question 2

A patient is experiencing muscle weakness due to a malfunction in their sodium-potassium pumps. Which of the following would most likely be observed in their neurons?

Accepted Answer

The resting membrane potential would become more positive than normal.

Question 3

Which equation would you use to calculate the equilibrium potential for potassium ions across a neuronal membrane?

Accepted Answer

Nernst equation

Question 4

During which phase of the action potential are voltage-gated sodium channels inactivated and a stronger-than-normal stimulus is required to trigger another action potential?

Accepted Answer

Relative refractory period

Question 5

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

Accepted Answer

Pacemaker cell in the SA node

Question 6

A neuron receives several small excitatory postsynaptic potentials (EPSPs) that do not individually reach threshold. What is the most likely outcome?

Accepted Answer

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

Question 7

Which of the following best describes the function of osmoreceptors?

Accepted Answer

They detect changes in osmotic pressure or solute concentration.

Question 8

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

Accepted Answer

Free nerve endings

Question 9

Which cranial nerve is purely sensory and responsible for transmitting visual information to the brain?

Accepted Answer

Optic nerve

Question 10

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

Accepted Answer

Referred pain

Question 11

Which of the following statements about the all-or-none principle of action potentials is correct?

Accepted Answer

Once threshold is reached, an action potential always occurs with the same magnitude.

Question 12

Which of the following best explains why the somatosensory cortex allocates more space to the hands and lips than to the back?

Accepted Answer

The hands and lips have more sensory receptors and higher sensitivity.

Question 13

If the extracellular concentration of potassium increases significantly, what is the most likely effect on the resting membrane potential of a neuron?

Accepted Answer

It becomes less negative (depolarized).

Question 14

Which of the following best describes the role of astrocytes in the nervous system?

Accepted Answer

They help maintain the blood-brain barrier and regulate blood flow.

Question 15

A researcher wants to calculate the resting membrane potential of a neuron considering the permeability of multiple ions. Which equation should they use?

Accepted Answer

Goldman-Hodgkin-Katz equation

Question 16

Which of the following is a property of tonic receptors?

Accepted Answer

They continue to respond to prolonged or continuous stimuli.

Question 17

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

Accepted Answer

A postsynaptic neuron receives varying levels of depolarization depending on the amount of neurotransmitter released.

Question 18

Which of the following would most likely occur if chloride channels in a neuron's membrane opened and remained open longer than usual after an action potential?

Accepted Answer

The neuron would become hyperpolarized.

Question 19

Which of the following best describes the function of endothelial cells in the context of neural signaling?

Accepted Answer

They line blood vessels and interact with blood and other tissues.

Question 20

A neuron has a resting membrane potential of -70 mV and a threshold of -55 mV. If a stimulus depolarizes the membrane to -60 mV, what will happen?

Accepted Answer

A graded potential will occur, but no action potential will be generated.

Resting Membrane Potential and Neural Signaling: Key Concepts for GOB Chemistry

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