$$CO = HR \times SV = 90 \times 60 = 5400\,ml/min$$

Question 1

Which chamber of the heart receives oxygen-poor blood from the body via the superior and inferior vena cava?

Accepted Answer

Right atrium

Question 2

What is the primary function of the chordae tendineae in the heart?

Accepted Answer

To anchor the AV valves and prevent them from inverting into the atria during ventricular contraction

Question 3

During ventricular systole, which valves are open and which are closed?

Accepted Answer

AV valves closed, semilunar valves open

Question 4

Which artery supplies blood to the interventricular septum and anterior walls of both ventricles?

Accepted Answer

Anterior interventricular artery (left anterior descending)

Question 5

If the left ventricle fails to pump blood effectively, which circuit is most directly affected?

Accepted Answer

Systemic circuit

Question 6

Which of the following best describes the relationship between cardiac output (CO), heart rate (HR), and stroke volume (SV)?

Accepted Answer

CO = HR 	imes SV

Question 7

A patient has a heart rate of 90 beats/min and a stroke volume of 60 ml/beat. What is their cardiac output?

Accepted Answer

$$CO = HR 	imes SV = 90 	imes 60 = 5400\,ml/min$$

Question 8

Which structure is known as the heart’s pacemaker and initiates the electrical impulses for contraction?

Accepted Answer

SA node

Question 9

What does the QRS complex on an electrocardiogram (ECG) represent?

Accepted Answer

Ventricular contraction (depolarization)

Question 10

Which of the following would most likely increase heart rate via the sympathetic nervous system?

Accepted Answer

Release of norepinephrine

Question 11

Which layer of the heart wall is composed primarily of cardiac muscle and is responsible for the force of contraction?

Accepted Answer

Myocardium

Question 12

If a patient has a weakened heart muscle and their stroke volume decreases, what compensatory mechanism will the body use to maintain cardiac output?

Accepted Answer

Increase heart rate and contractility

Question 13

Which of the following is TRUE regarding the pulmonary circuit?

Accepted Answer

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

Question 14

Which of the following best describes the function of the semilunar valves?

Accepted Answer

Prevent backflow of blood into the ventricles

Question 15

Which vein returns blood from the myocardium to the right atrium?

Accepted Answer

Coronary sinus

Question 16

A patient’s ECG shows an abnormal QRS complex. Which part of the heart’s conduction system is most likely affected?

Accepted Answer

Bundle branches or Purkinje fibers

Question 17

Which hormone increases both heart rate and contractility, and also enhances the effects of epinephrine?

Accepted Answer

Thyroid hormone

Question 18

Which of the following statements about the cardiac cycle is correct?

Accepted Answer

Atrial systole precedes ventricular systole

Question 19

Which of the following would most likely result from a blockage in the left anterior descending coronary artery?

Accepted Answer

Reduced blood flow to the interventricular septum and anterior walls of both ventricles

Question 20

Which of the following best explains why the left ventricle wall is thicker than the right ventricle wall?

Accepted Answer

The left ventricle pumps blood to the entire body, requiring higher pressure

Chapter 18: The Cardiovascular System – The Heart

Study Guide - Practice Questions