Anatomy Exam Anatomy of the Heart 2 — Questions and Answers
Question 1: Which layer of the heart wall is responsible for the actual pumping action?
- Epicardium
- Myocardium (Correct answer)
- Endocardium
- Pericardium
Correct answer: Myocardium
The myocardium is the thick muscular middle layer of the heart wall that contracts to pump blood.
Question 2: What is the name of the depression on the interatrial septum that represents the remnant of the fetal foramen ovale?
- Fossa ovalis (Correct answer)
- Crista terminalis
- Limbus fossae ovalis
- Trabeculae carneae
Correct answer: Fossa ovalis
The fossa ovalis is an oval-shaped depression in the right atrium's interatrial septum, marking where the foramen ovale closed after birth.
Question 3: Which coronary artery supplies the SA node in most individuals?
- Left anterior descending artery
- Left circumflex artery
- Right coronary artery (Correct answer)
- Posterior descending artery
Correct answer: Right coronary artery
The right coronary artery supplies the SA node in approximately 60% of individuals.
Question 4: The moderator band (septomarginal trabecula) carries which structure across the right ventricular cavity?
- Chordae tendineae
- Part of the right bundle branch (Correct answer)
- Papillary muscle fibers
- Coronary sinus
Correct answer: Part of the right bundle branch
The moderator band carries the right bundle branch of the cardiac conduction system from the interventricular septum to the anterior papillary muscle.
Question 5: Which surface of the heart rests on the diaphragm?
- Anterior (sternocostal) surface
- Inferior (diaphragmatic) surface (Correct answer)
- Left pulmonary surface
- Posterior (base) surface
Correct answer: Inferior (diaphragmatic) surface
The inferior (diaphragmatic) surface of the heart, formed mainly by the left ventricle, rests on the diaphragm.
Question 6: What prevents backflow of blood from the aorta into the left ventricle?
- Mitral valve
- Tricuspid valve
- Aortic semilunar valve (Correct answer)
- Pulmonary semilunar valve
Correct answer: Aortic semilunar valve
The aortic semilunar valve closes during ventricular relaxation (diastole) to prevent backflow of blood from the aorta into the left ventricle.
Question 7: Which chamber of the heart has the thickest wall and why?
- Right atrium, because it receives all systemic venous blood
- Left ventricle, because it pumps blood against high systemic resistance (Correct answer)
- Right ventricle, because it pumps blood to the lungs
- Left atrium, because it receives oxygenated blood from the lungs
Correct answer: Left ventricle, because it pumps blood against high systemic resistance
The left ventricle has the thickest wall (~11–14 mm) because it must generate sufficient pressure to pump blood through the entire systemic circulation.
Anatomy Exam Anatomy of the Heart 2
Which layer of the heart wall is responsible for the actual pumping action?