$$CO = 80 \times 60 = 4800\,mL/min$$

Question 1

Which layer of the heart wall is responsible for the contractile function of the heart and contains spiral bundles of cardiac muscle cells?

Accepted Answer

Myocardium

Question 2

A patient presents with chest pain due to a fleeting deficiency in blood delivery to the myocardium. What is the most likely diagnosis?

Accepted Answer

Angina pectoris

Question 3

Which of the following best describes the function of the chordae tendineae?

Accepted Answer

They prevent the AV valve cusps from everting into the atria during ventricular contraction.

Question 4

During which phase of the cardiac cycle are all heart valves closed and the ventricles are neither filling nor ejecting blood?

Accepted Answer

Isovolumetric contraction

Question 5

Which equation correctly represents cardiac output (CO)?

Accepted Answer

$$CO = HR 	imes SV$$

Question 6

If a patient has an end diastolic volume (EDV) of 120 mL and an end systolic volume (ESV) of 50 mL, what is their stroke volume (SV)?

Accepted Answer

$$SV = 120\,mL - 50\,mL = 70\,mL$$

Question 7

Which of the following is a direct effect of increased sympathetic stimulation on the heart?

Accepted Answer

Increased heart rate and contractility

Question 8

A blockage in the left anterior descending (LAD) artery would most likely affect which region of the heart?

Accepted Answer

Anterior wall of the left ventricle

Question 9

Which of the following statements about the pulmonary circuit is correct?

Accepted Answer

It carries blood to and from the lungs for gas exchange.

Question 10

Which event is represented by the QRS complex on an electrocardiogram (ECG)?

Accepted Answer

Ventricular depolarization

Question 11

A patient with persistent high blood pressure is at risk for which change in the heart?

Accepted Answer

Increased afterload

Question 12

Which of the following best explains why the left ventricle has a thicker myocardium than the right ventricle?

Accepted Answer

It must generate more force to overcome greater resistance in the systemic circuit.

Question 13

Which of the following is a function of the fibrous skeleton of the heart?

Accepted Answer

Anchors cardiac muscle fibers and supports valves

Question 14

Which of the following would most likely result from a defective SA node?

Accepted Answer

Junctional rhythm with a heart rate of 40–60 bpm

Question 15

Which of the following best describes the Frank-Starling law of the heart?

Accepted Answer

The greater the preload, the greater the force of contraction.

Question 16

Which of the following is a positive inotropic agent that increases contractility of the heart?

Accepted Answer

Epinephrine

Question 17

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

Accepted Answer

$$CO = 80 	imes 60 = 4800\,mL/min$$

Question 18

Which of the following is true regarding the absolute refractory period in cardiac muscle?

Accepted Answer

It prevents tetanus by being much longer than in skeletal muscle.

Question 19

Which of the following best describes the effect of acetylcholine on pacemaker cells?

Accepted Answer

It hyperpolarizes the membrane by increasing K+ efflux, decreasing heart rate.

Question 20

Which of the following is a likely consequence of a myocardial infarction?

Accepted Answer

Formation of noncontractile scar tissue in the myocardium

The Cardiovascular System: The Heart – Structure, Function, and Physiology

Study Guide - Practice Questions