Question 1

Which of the following best describes homeostasis in the human body?

Accepted Answer

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

Question 2

A patient is experiencing a drop in blood glucose levels. Which of the following best illustrates the body's response to restore homeostasis?

Accepted Answer

The pancreas releases glucagon, which stimulates the liver to convert glycogen to glucose.

Question 3

Which of the following substances can freely cross the lipid bilayer of a cell membrane?

Accepted Answer

Small, nonpolar molecules such as $$\mathrm{O_2$}$$ and $$\mathrm{CO_2$}$$

Question 4

Which of the following is NOT a factor that affects the rate of diffusion across a membrane?

Accepted Answer

The number of mitochondria in the cell

Question 5

A cell is placed in a solution with a higher osmolarity than its cytoplasm. What will most likely happen to the cell?

Accepted Answer

Water will move out of the cell, causing it to shrink.

Question 6

Which equation best represents the rate of diffusion according to Fick's Law?

Accepted Answer

$$J = -D \frac{\Delta C}{\Delta x}$$

Question 7

Which statement about osmolarity is correct when using the 'compare' form?

Accepted Answer

You must specify both the solution and the reference compartment (e.g., cell cytoplasm).

Question 8

Which of the following best explains why osmolarity and tonicity can differ?

Accepted Answer

Some solutes are impermeable to the cell membrane, affecting tonicity but not osmolarity.

Question 9

A solution contains 0.5 mol/L NaCl and 0.5 mol/L glucose. What is the total osmolarity of the solution?

Accepted Answer

$$1.5\ \mathrm{osm/L}$$

Question 10

Which of the following is a regulated variable in homeostasis?

Accepted Answer

Blood pressure

Question 11

Which scenario best illustrates the interaction between different levels of physiological organization?

Accepted Answer

A hormone released by an endocrine gland affects the function of multiple organs.

Question 12

Which of the following is NOT a major fluid compartment in the human body?

Accepted Answer

Lymphatic fluid

Question 13

A patient receives an intravenous solution containing only impermeant solutes. What effect will this have on the patient's cells?

Accepted Answer

The solution will affect tonicity, causing water movement across cell membranes.

Question 14

Which of the following best describes osmosis?

Accepted Answer

The movement of water across a semipermeable membrane from an area of low solute concentration to high solute concentration.

Question 15

Which factor does NOT directly affect osmosis?

Accepted Answer

The number of mitochondria in the cell

Question 16

A cell is placed in a hypotonic solution. What is the expected outcome?

Accepted Answer

Water will enter the cell, causing it to swell.

Question 17

Which of the following is the correct formula for calculating osmolarity?

Accepted Answer

$$	ext{Osmolarity} = \sum_{i} c_i 	imes n_i$$

Question 18

Which of the following best describes the relationship between osmolarity and tonicity?

Accepted Answer

Osmolarity measures total solute concentration, while tonicity considers only solutes that cannot cross the membrane.

Question 19

A patient is given a solution with a higher tonicity than their blood plasma. What is the most likely effect on their red blood cells?

Accepted Answer

The cells will lose water and shrink.

Question 20

Which of the following is an example of a multi-step physiological process involving membrane transport and homeostasis?

Accepted Answer

The regulation of blood sodium levels by the kidneys, involving diffusion, active transport, and hormonal control.

Week #1

Study Guide - Practice Questions