Question 1

Which of the following best describes the difference between osmotic equilibrium and chemical equilibrium in the context of body fluids?

Accepted Answer

Osmotic equilibrium is when water concentrations are equal across compartments, while chemical equilibrium is when solute concentrations are equal across compartments.

Question 2

A patient is given an intravenous solution that is hypertonic relative to their intracellular fluid. What is the most likely effect on their cells?

Accepted Answer

Water will leave the cells, causing them to shrink.

Question 3

Which equation is used to calculate the equilibrium potential for potassium ions across a cell membrane?

Accepted Answer

$$E_K = \frac{RT}{zF} \ln \left( \frac{[K^+]_{out}}{[K^+]_{in}} \right)$$

Question 4

Which of the following is a correct example of secondary active transport?

Accepted Answer

Glucose transport into a cell using the Na+ gradient established by the sodium-potassium pump.

Question 5

A researcher blocks all gap junctions between cardiac muscle cells. Which type of cellular communication is most directly affected?

Accepted Answer

Contact-dependent communication

Question 6

Which of the following best describes the role of the sodium-potassium pump in maintaining the resting membrane potential?

Accepted Answer

It pumps Na+ out of the cell and K+ into the cell, creating and maintaining ion gradients.

Question 7

Which of the following is an example of an antagonist in signal transduction?

Accepted Answer

A molecule that blocks a receptor and prevents its activation.

Question 8

A cell is exposed to a lipophilic signaling molecule. Which of the following is most likely to occur?

Accepted Answer

The molecule diffuses through the membrane and binds to an intracellular receptor.

Question 9

Which of the following best explains why facilitated diffusion is considered a passive process?

Accepted Answer

It uses carrier proteins to move molecules down their concentration gradient without energy input.

Question 10

A neuron has a resting membrane potential of $$-70 mV. $$Which of the following factors contributes most to this value?

Accepted Answer

High permeability of the membrane to potassium ions and the activity of the Na+/K+ pump.

Question 11

Which of the following is an example of tonic control in homeostatic regulation?

Accepted Answer

The heart rate is regulated by a single system that can increase or decrease its output.

Question 12

Which of the following best describes the function of second messengers such as $$cAMP in $$signal transduction?

Accepted Answer

They relay and amplify signals from membrane receptors to intracellular targets.

Question 13

A cell is exposed to a chemical that blocks exocytosis. Which process would be most directly impaired?

Accepted Answer

Release of neurotransmitters into the synaptic cleft.

Question 14

Which of the following is a correct example of an amplification step in a signaling cascade?

Accepted Answer

A single hormone molecule binding to a receptor leads to the activation of many intracellular enzymes.

Question 15

Which of the following best describes the difference between paracrine and endocrine signaling?

Accepted Answer

Paracrine signals act on nearby cells, while endocrine signals are transported through the bloodstream to distant targets.

Question 16

A cell is placed in a solution and water moves into the cell, causing it to swell. Which term best describes the solution?

Accepted Answer

Hypotonic

Question 17

Which of the following is a feature of homeostatic control systems according to Cannon's postulates?

Accepted Answer

Antagonistic control involves opposing effects by different systems.

Question 18

Which of the following best describes the function of carrier proteins in membrane transport?

Accepted Answer

They bind specific molecules and undergo conformational changes to transport them across the membrane.

Question 19

A signaling molecule binds to a G protein-coupled receptor (GPCR) and activates adenylyl cyclase. Which second messenger is produced as a result?

Accepted Answer

$$cAMP$$

Question 20

Which of the following is an example of a novel signal molecule mentioned in the study materials?

Accepted Answer

Nitric oxide

Homeostasis, Membrane Transport, and Cellular Communication: Study Notes for Anatomy & Physiology

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