$$\text{Cardiac Output} = \text{Heart Rate} \times \text{Stroke Volume}$$

Question 1

Which of the following correctly lists the three layers of the heart wall from outermost to innermost?

Accepted Answer

Epicardium, myocardium, endocardium

Question 2

What is the primary function of the precapillary sphincter in the regulation of blood flow?

Accepted Answer

To control the amount of blood entering a capillary bed

Question 3

Which chamber of the heart has the thickest myocardium and why?

Accepted Answer

Left ventricle, because it must generate high pressure to pump blood into the aorta

Question 4

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

Accepted Answer

It acts as the heart's pacemaker by initiating electrical impulses

Question 5

During which phase of the cardiac cycle do the ventricles contract and the atrioventricular (AV) valves close?

Accepted Answer

Ventricular systole

Question 6

Which equation correctly represents cardiac output?

Accepted Answer

$$	ext{Cardiac Output} = 	ext{Heart Rate} 	imes 	ext{Stroke Volume}$$

Question 7

A patient has a resting heart rate of 80 beats per minute and a stroke volume of 65 mL/beat. What is their cardiac output?

Accepted Answer

$$5200\ 	ext{mL/min}$$

Question 8

Which of the following mechanisms does NOT assist in returning blood to the heart through the veins?

Accepted Answer

Elastic recoil of arteries

Question 9

Which of the following is a direct result of increased metabolic activity in tissues, as shown in the diagram?

Accepted Answer

Vasodilation of arterioles and precapillary sphincters

Question 10

Which of the following statements about the lymphatic system is TRUE?

Accepted Answer

It returns excess interstitial fluid to the bloodstream and plays a role in immune defense

Question 11

A patient is diagnosed with hypertension. Which of the following is a likely consequence if left untreated?

Accepted Answer

Increased risk of heart attack, stroke, and kidney damage

Question 12

Which of the following best explains why veins have valves but arteries do not?

Accepted Answer

Veins operate under lower pressure and need valves to prevent backflow due to gravity

Question 13

Which event is responsible for the first heart sound ("lub") heard during the cardiac cycle?

Accepted Answer

Closure of the atrioventricular (AV) valves during ventricular systole

Question 14

Which of the following best describes the function of baroreceptors?

Accepted Answer

They detect changes in arterial pressure and help regulate blood pressure

Question 15

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

Accepted Answer

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

Question 16

Which of the following is a likely cause of an aneurysm?

Accepted Answer

Weakening of the arterial wall, leading to ballooning and potential rupture

Question 17

Which of the following best describes the QRS complex in an electrocardiogram (ECG)?

Accepted Answer

It represents the spread of electrical impulse through the ventricles, causing ventricular systole

Question 18

A patient experiences a blockage in a coronary artery. Which condition is most likely to result?

Accepted Answer

Myocardial infarction (heart attack)

Question 19

Which of the following is a function of the pericardium?

Accepted Answer

It protects the heart and prevents overfilling with blood

Question 20

Which of the following best explains why capillaries are the only blood vessels where exchange of gases and nutrients occurs?

Accepted Answer

They have thin, porous walls and a single layer of squamous epithelial cells

The Heart and Blood Vessels: Structure, Function, and Regulation

Study Guide - Practice Questions