Question 1

Which of the following best describes the anatomical location of the heart within the thorax?

Accepted Answer

The heart is located in the mediastinum, between the lungs, posterior to the sternum, and superior to the diaphragm.

Question 2

Which structure is responsible for preventing friction between the heart and surrounding tissues during contraction?

Accepted Answer

The pericardium, specifically its serous layer, produces pericardial fluid to reduce friction.

Question 3

A patient presents with chest pain and a friction rub heard on auscultation. Which condition is most likely, and what is its primary cause?

Accepted Answer

Pericarditis, most commonly caused by viral infection or autoimmune reaction.

Question 4

Which histological feature of cardiac muscle allows for rapid and coordinated contraction?

Accepted Answer

Intercalated discs, which contain gap junctions and desmosomes.

Question 5

Cardiac hypertrophy is best defined as:

Accepted Answer

An increase in the size of cardiac muscle cells, often due to chronic pressure overload such as hypertension.

Question 6

Which sequence correctly describes the flow of blood through the heart?

Accepted Answer

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

Question 7

The S1 heart sound is primarily caused by:

Accepted Answer

Closure of the atrioventricular (AV) valves at the beginning of ventricular systole.

Question 8

Mitral valve prolapse (MVP) is best described as:

Accepted Answer

A condition where the mitral valve leaflets bulge into the left atrium during systole, often due to connective tissue abnormalities.

Question 9

Coronary artery disease (CAD) is primarily caused by:

Accepted Answer

Atherosclerosis, which is the buildup of plaque in the coronary arteries.

Question 10

Which blood test is most specific for diagnosing a myocardial infarction (MI)?

Accepted Answer

Troponin I, which rises within hours and is highly specific for cardiac muscle injury.

Question 11

Which is the correct pathway for electrical conduction in the heart?

Accepted Answer

SA node → AV node → Bundle of His → Right and Left Bundle Branches → Purkinje fibers

Question 12

During which phase of the ECG does ventricular depolarization occur?

Accepted Answer

QRS complex

Question 13

Why are slow calcium channels important in cardiac muscle compared to skeletal muscle?

Accepted Answer

They prolong the action potential, allowing for sustained contraction and preventing tetany.

Question 14

ST segment elevation on an ECG is most indicative of:

Accepted Answer

Acute myocardial infarction due to transmural ischemia.

Question 15

Which equation correctly represents cardiac output ($$CO$$)?

Accepted Answer

$$CO = HR 	imes SV$$

Question 16

A patient has a heart rate ($$HR) of 80 $$beats per minute and a stroke volume ($$SV) of 70 mL. $$What is their cardiac output ($$CO$$)?

Accepted Answer

$$CO = 80 	imes 70 = 5600\ 	ext{mL/min}$$

Question 17

Which hormone is released by the atria in response to increased blood volume and acts to decrease blood pressure?

Accepted Answer

Atrial natriuretic peptide (ANP)

Question 18

Which of the following best describes preload in cardiac physiology?

Accepted Answer

The degree of stretch of the ventricular myocardium at the end of diastole, determined by venous return.

Question 19

A patient with congestive heart failure (CHF) has an ejection fraction ($$EF) of 35$$%. If their end-diastolic volume ($$EDV) is 120 mL$$, what is their stroke volume ($$SV$$)? Use the formula $$EF = \frac{SV}{EDV} 	imes 100\%.$$

Accepted Answer

$$SV = \frac{EF}{100\%} 	imes EDV = \frac{35}{100} 	imes 120 = 42\ 	ext{mL}$$

Study Guide: The Heart (Chapter 20) – Structure, Function, and Clinical Aspects

Study Guide - Practice Questions

Study Guide - Flashcards