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

$E = \frac{RT}{zF} \ln \left( \frac{[\text{ion}]_{\text{out}}}{[\text{ion}]_{\text{in}}} \right)$

Question 1

Which of the following best defines homeostasis in the context of human physiology?

Accepted Answer

The process by which the body maintains a stable internal environment despite changes in external conditions.

Question 2

Which of the following is NOT a primary tissue type found in the human body?

Accepted Answer

Adipose tissue

Question 3

A patient is experiencing rapid loss of sodium ions from their cells. Which passive transport mechanism is most likely responsible for this movement?

Accepted Answer

Facilitated diffusion

Question 4

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

Accepted Answer

$E = \frac{RT}{zF} \ln \left( \frac{[	ext{ion}]_{	ext{out}}}{[	ext{ion}]_{	ext{in}}} ight)$

Question 5

Which of the following best describes the role of negative feedback in maintaining homeostasis?

Accepted Answer

It reverses the direction of the change to bring the system back to its set point.

Question 6

Which of the following is a correct sequence of events in G protein-linked signal transduction?

Accepted Answer

Ligand binds receptor → G protein activated → Effector enzyme activated → Second messenger produced

Question 7

Which of the following best describes the difference between graded potentials and action potentials?

Accepted Answer

Graded potentials can summate and decrease with distance, while action potentials are propagated without decrement.

Question 8

Which of the following types of gated ion channels is primarily responsible for the rapid depolarization phase of the action potential?

Accepted Answer

Voltage-gated sodium channels

Question 9

A neuron is unable to fire a second action potential immediately after the first. Which property of the axon membrane is responsible for this phenomenon?

Accepted Answer

Absolute refractory period

Question 10

Which of the following equations correctly represents the relationship between current ($I$), voltage ($V$), and resistance ($R$) in a neuron?

Accepted Answer

$I = \frac{V}{R}$

Question 11

Which of the following best describes the function of myelin in the nervous system?

Accepted Answer

It increases the speed of action potential conduction by insulating axons.

Question 12

Which of the following is a correct description of a chemical synapse?

Accepted Answer

A junction where neurotransmitters are released from the presynaptic neuron to bind receptors on the postsynaptic cell.

Question 13

Which of the following best explains the difference between afferent and efferent neurons?

Accepted Answer

Afferent neurons carry sensory information to the central nervous system, while efferent neurons carry motor commands away from it.

Question 14

Which of the following is NOT a function of astrocytes in the central nervous system?

Accepted Answer

Generating action potentials

Question 15

Which of the following best describes the process of signal transduction for membrane enzymes such as tyrosine kinase?

Accepted Answer

Ligand binding activates the enzyme, which phosphorylates target proteins to initiate a cellular response.

Question 16

Which of the following is a correct description of the role of gap junctions in cellular communication?

Accepted Answer

They allow direct passage of ions and small molecules between adjacent cells.

Question 17

Which of the following best describes the difference between autocrine, paracrine, and endocrine modes of chemical signaling?

Accepted Answer

Autocrine signals act on the same cell that secreted them; paracrine signals act on nearby cells; endocrine signals travel through the bloodstream to distant cells.

Question 18

Which of the following is a correct description of the mechanism by which facilitated diffusion carrier proteins move molecules across the membrane?

Accepted Answer

Carrier proteins bind specific molecules and undergo a conformational change to transport them down their concentration gradient.

Question 19

Which of the following best describes the process of depolarization in a neuron?

Accepted Answer

The membrane potential becomes less negative due to the influx of sodium ions.

Fundamental Concepts in Anatomy & Physiology: Cells, Tissues, Membranes, and Neural Signaling

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