Question 1

Which of the following best describes the function of the right side of the heart?

Accepted Answer

It receives deoxygenated blood from the body and pumps it to the lungs.

Question 2

Which layer of the heart wall is primarily responsible for the heart's contractile function?

Accepted Answer

Myocardium

Question 3

A patient has a blockage in the right marginal artery. Which area of the heart is most likely to be affected?

Accepted Answer

Lateral right side of the heart

Question 4

Which of the following statements about cardiac muscle cells is correct?

Accepted Answer

They are short, branched, and connected by intercalated discs.

Question 5

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

Accepted Answer

AV valves are closed; SL valves are open.

Question 6

A patient has a heart rate of 80 beats per minute and a stroke volume of 70 mL. What is their cardiac output? Use the formula $$CO = HR 	imes SV.$$

Accepted Answer

$$5600\ \mathrm{mL/min}$$

Question 7

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

Accepted Answer

It must generate higher pressure to overcome greater resistance in the systemic circulation.

Question 8

Which event occurs during the plateau phase of a cardiac muscle cell action potential?

Accepted Answer

Influx of $$Ca^{2+}$$ ions

Question 9

A patient is diagnosed with aortic valve stenosis, which increases afterload. How will this most likely affect stroke volume, assuming all other factors remain constant?

Accepted Answer

Stroke volume will decrease because the ventricle must work harder to eject blood.

Question 10

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

Accepted Answer

It acts as the heart's pacemaker, initiating each heartbeat.

Question 11

Which of the following changes would most likely increase cardiac output during exercise?

Accepted Answer

Increased heart rate and increased stroke volume

Question 12

Which of the following is a function of the fibrous pericardium?

Accepted Answer

It anchors the heart and prevents overfilling.

Question 13

A patient has a mutation that causes their cardiac muscle cells to lack gap junctions. Which of the following would most likely occur?

Accepted Answer

Electrical impulses would not spread efficiently, leading to uncoordinated contractions.

Question 14

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

Accepted Answer

The greater the stretch of cardiac muscle cells before contraction, the stronger the force of contraction.

Question 15

Which of the following is a likely consequence of atherosclerosis in the coronary arteries?

Accepted Answer

Reduced oxygen supply to cardiac muscle, potentially leading to myocardial infarction

Question 16

Which of the following best explains why cardiac muscle cells have a longer absolute refractory period than skeletal muscle cells?

Accepted Answer

To prevent tetanic contractions and ensure proper heart function

Question 17

A patient has a heart murmur due to a leaky mitral valve. Which of the following best describes the likely effect?

Accepted Answer

Blood will flow backward from the left ventricle into the left atrium during ventricular contraction.

Question 18

Which of the following best describes the effect of parasympathetic stimulation on the heart?

Accepted Answer

It decreases heart rate by increasing membrane permeability to $$K^+.$$

Question 19

Which of the following is the correct sequence of structures that a cardiac action potential travels through, starting at the SA node?

Accepted Answer

SA node → AV node → bundle branches → Purkinje fibers

Question 20

A patient has a heart rate of 60 beats per minute and an end-diastolic volume (EDV) of 120 mL and an end-systolic volume (ESV) of 50 mL. What is their cardiac output? Use the formulas $$SV = EDV - ESV$$ and $$CO = HR 	imes SV.$$

Accepted Answer

$$4200\ \mathrm{mL/min}$$

Cardiac Anatomy and Physiology: Structure, Function, and Regulation of the Heart

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