Question 1

Which layer of the heart wall is primarily responsible for the heart's ability to contract and pump blood?

Accepted Answer

Myocardium

Question 2

Blood returning from the lungs enters the heart through which chamber?

Accepted Answer

Left atrium

Question 3

Which valve prevents backflow of blood from the right ventricle to the right atrium during ventricular contraction?

Accepted Answer

Tricuspid valve

Question 4

During the cardiac cycle, what event is represented by the QRS complex on an electrocardiogram (ECG)?

Accepted Answer

Ventricular depolarization

Question 5

Which of the following best describes the function of the baroreceptor reflex?

Accepted Answer

Maintains homeostasis in response to changes in blood pressure

Question 6

If the end-diastolic volume (EDV) is 120 mL and the end-systolic volume (ESV) is 50 mL, what is the stroke volume (SV)?

$$SV = EDV - ESV$$

Accepted Answer

70 mL

Question 7

Which of the following statements about cardiac muscle is TRUE?

Accepted Answer

Cardiac muscle cells are connected by intercalated disks, allowing action potentials to spread from cell to cell.

Question 8

Which of the following would most likely result from an increase in extracellular potassium (K$$^+) $$concentration?

Accepted Answer

Decreased heart rate and possible heart block

Question 9

A patient presents with a narrowed opening in the pulmonary valve, resulting in increased workload for the right ventricle. What is the most likely diagnosis?

Accepted Answer

Pulmonary stenosis

Question 10

Which equation correctly represents mean arterial pressure (MAP) in terms of cardiac output (CO) and peripheral resistance (PR)?

$$MAP = CO 	imes PR$$

Accepted Answer

$$MAP = CO 	imes PR$$

Question 11

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

Accepted Answer

Prevents overdistention of the heart and acts as an anchor

Question 12

Which structure is known as the pacemaker of the heart?

Accepted Answer

Sinoatrial (SA) node

Question 13

During which phase of the cardiac muscle action potential does the plateau occur, and what ion is primarily responsible for this phase?

Accepted Answer

Plateau phase; calcium (Ca$$^{2+})$$

Question 14

Which of the following best explains Starling’s law of the heart?

Accepted Answer

The greater the stretch of the ventricular walls (preload), the greater the force of contraction.

Question 15

A patient with myocardial infarction is most likely experiencing which of the following?

Accepted Answer

Damaged cardiac muscle tissue due to lack of blood flow to the myocardium

Question 16

Which of the following is TRUE regarding the conduction system of the heart?

Accepted Answer

The Purkinje fibers rapidly conduct action potentials to ventricular muscle cells.

Question 17

Which heart sound is associated with the closure of the atrioventricular (AV) valves?

Accepted Answer

First heart sound (lubb)

Question 18

Which of the following would most likely increase cardiac output (CO)?

Accepted Answer

Increased heart rate and increased stroke volume

Question 19

Which of the following is a consequence of prolonged lowered oxygen levels detected by chemoreceptors?

Accepted Answer

Increased heart rate and blood pressure to deliver more oxygen to tissues

Question 20

Which of the following is a plausible effect of aging on the heart?

Accepted Answer

Decreased hormone effects and increased arrhythmias

Anatomy and Physiology of the Heart: Structure, Function, and Circulation

Guida di studio - Domande di pratica

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