Question 1

Which of the following best explains why diffusion is only efficient over small distances in biological systems?

Accepted Answer

Because the time to diffuse is proportional to the square of the distance, $$t \propto d^2$

Question 2

Which statement correctly distinguishes open and closed circulatory systems?

Accepted Answer

In open systems, circulatory fluid bathes organs directly; in closed systems, fluid is confined to vessels and is distinct from interstitial fluid

Question 3

In the mammalian heart, which structure is responsible for setting the rate and timing of cardiac muscle contractions?

Accepted Answer

Sinoatrial (SA) node

Question 4

Which equation correctly represents cardiac output ($$CO) in $$terms of heart rate ($$HR) $$and stroke volume ($$SV$$)?

Accepted Answer

$$CO = HR 	imes SV$$

Question 5

A patient has a blood pressure reading of 120/80 mmHg. What do the numbers 120 and 80 represent?

Accepted Answer

120 is systolic pressure, 80 is diastolic pressure

Question 6

Which of the following would most likely result in an increase in arterial blood pressure?

Accepted Answer

Vasoconstriction of arterioles

Question 7

Which blood vessel carries oxygen-rich blood from the lungs to the left atrium of the heart?

Accepted Answer

Pulmonary vein

Question 8

What is the primary function of platelets in the blood?

Accepted Answer

Facilitate blood clotting

Question 9

A person with sickle-cell disease has abnormal hemoglobin proteins. What is a direct consequence of this abnormality?

Accepted Answer

Deformation of erythrocytes into a sickle shape, leading to vessel blockage and pain

Question 10

Which of the following is a correct sequence of blood flow through the mammalian heart and lungs?

Accepted Answer

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

Question 11

Which plasma protein is converted to fibrin during the process of blood clotting?

Accepted Answer

Fibrinogen

Question 12

What is the main function of lymph nodes in the lymphatic system?

Accepted Answer

Filter lymph and play a role in immune defense

Question 13

Which of the following best describes the difference between arteries and veins?

Accepted Answer

Arteries carry blood away from the heart; veins carry blood toward the heart

Question 14

Which of the following is a risk factor for atherosclerosis and cardiovascular disease?

Accepted Answer

High levels of LDL cholesterol

Question 15

If a person’s stroke volume is 70 mL and their heart rate is 75 beats per minute, what is their cardiac output?

Accepted Answer

$$5250\ \mathrm{mL/min}$$

Question 16

Which of the following would most likely occur if the semilunar valves of the heart failed to close properly?

Accepted Answer

Blood would flow backward from the arteries into the ventricles, causing a heart murmur

Question 17

Which of the following is true about the velocity of blood flow in capillaries?

Accepted Answer

It is lowest in capillaries due to their large total cross-sectional area

Question 18

Which of the following is a consequence of hypertension (high blood pressure)?

Accepted Answer

Increased risk of heart attack and stroke

Question 19

Which of the following best describes the role of the endothelium in blood vessels?

Accepted Answer

It lines the blood vessels and minimizes resistance to blood flow

Circulation and Gas Exchange: Structure and Function of the Cardiovascular System

Study Guide - Practice Questions