Question 1

Which specialized structure is responsible for gas exchange in the animal shown in the first image (with red feathery appendages)?

Accepted Answer

Gills

Question 2

In animals with a closed circulatory system, which of the following statements is TRUE?

Accepted Answer

Blood is confined to vessels and is separate from interstitial fluid

Question 3

Which equation best represents cardiac output ($$CO) in $$humans?

Accepted Answer

$$CO = HR 	imes SV$$

Question 4

A patient has a heart rate of 80 beats per minute and a stroke volume of 60 ml/beat. What is their cardiac output?

Accepted Answer

$$4800\ 	ext{ml/min}$$

Question 5

Which of the following best describes the function of the sinoatrial (SA) node?

Accepted Answer

It sets the rate and timing of cardiac muscle contraction

Question 6

What is the main advantage of a double circulatory system in mammals?

Accepted Answer

It ensures vigorous blood flow to organs by separating pulmonary and systemic circuits

Question 7

Which blood vessel has the thickest walls to withstand high pressure?

Accepted Answer

Arteries

Question 8

During vigorous exercise, a runner’s face becomes flushed. Which physiological process is most responsible?

Accepted Answer

Vasodilation

Question 9

Which equation describes the relationship between blood pressure ($$BP$$), cardiac output ($$CO$$), and peripheral resistance ($$PR$$)?

Accepted Answer

$$BP = CO 	imes PR$$

Question 10

Fluid exchange across capillary walls is regulated by which two pressures?

Accepted Answer

Hydrostatic pressure and osmotic pressure

Question 11

Which of the following is a function of the lymphatic system?

Accepted Answer

Returning interstitial fluid to the blood and storing white blood cells

Question 12

Which cellular element is most abundant in human blood and is responsible for oxygen transport?

Accepted Answer

Erythrocytes

Question 13

A blood clot that forms within a blood vessel and blocks blood flow is called:

Accepted Answer

Thrombus

Question 14

Which respiratory pigment is found in vertebrates and can bind up to four molecules of O$$_2$$?

Accepted Answer

Hemoglobin

Question 15

What is the effect of increased CO$$_2$$ production during exercise on blood pH and hemoglobin affinity for O$$_2$$?

Accepted Answer

Blood pH falls and hemoglobin releases O$$_2$$ more easily (Bohr shift)

Question 16

Which process describes the movement of gases across respiratory surfaces?

Accepted Answer

Diffusion down partial pressure gradients

Question 17

In fish gills, what is the main advantage of countercurrent exchange?

Accepted Answer

It maximizes O$$_2$$ uptake by maintaining a gradient along the entire gill

Question 18

Which of the following is TRUE about the pulmonary circuit in mammals?

Accepted Answer

It carries oxygen-poor blood from the right ventricle to the lungs

Question 19

Which of the following best describes the path of a red blood cell through the human heart, starting from the right atrium?

Accepted Answer

Right atrium → right ventricle → pulmonary artery → lungs → left atrium → left ventricle → aorta → body

Question 20

Which of the following is a major contributor to atherosclerosis?

Accepted Answer

High levels of LDL

Circulation and Gas Exchange in Animals

Study Guide - Practice Questions