Question 1

Which structure divides the mediastinum into superior and inferior portions?

Accepted Answer

The sternal angle

Question 2

A patient presents with pericardial effusion. Which layer of the pericardium is directly attached to the heart muscle?

Accepted Answer

Visceral layer of the serous pericardium

Question 3

During open heart surgery, a surgeon passes a finger behind the aorta and pulmonary trunk. Which pericardial sinus is being used as a passageway?

Accepted Answer

Transverse pericardial sinus

Question 4

Which of the following best describes the base of the heart?

Accepted Answer

It is formed mainly by the left atrium and faces posteriorly

Question 5

Which chamber of the heart receives deoxygenated blood from the systemic circulation?

Accepted Answer

Right atrium

Question 6

A defect in the tricuspid valve would most directly affect which of the following?

Accepted Answer

Blood flow from the right atrium to the right ventricle

Question 7

Which of the following best explains the function of the papillary muscles and chordae tendineae?

Accepted Answer

They prevent the atrioventricular valves from inverting during ventricular contraction

Question 8

Which valve prevents backflow of blood into the left ventricle after ventricular contraction?

Accepted Answer

Aortic (semilunar) valve

Question 9

During the cardiac cycle, which event is associated with the first heart sound ("lub")?

Accepted Answer

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

Question 10

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 11

Which of the following veins drains directly into the right atrium via the coronary sinus?

Accepted Answer

Great cardiac vein

Question 12

Which component of the cardiac conduction system is known as the heart's natural pacemaker?

Accepted Answer

Sinoatrial (SA) node

Question 13

On an electrocardiogram (ECG), which wave corresponds to ventricular depolarization?

Accepted Answer

QRS complex

Question 14

A patient with a block in the right vagus nerve superior to the cardiac plexus would most likely experience which of the following?

Accepted Answer

Increased heart rate

Question 15

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

Accepted Answer

Increases heart rate and force of contraction

Question 16

The thymus is most active during which period of life, and what is its primary function?

Accepted Answer

Childhood; maturation of T cells for immune function

Question 17

Which of the following equations best represents cardiac output ($$CO$$)?

Accepted Answer

$$CO = HR 	imes SV$$

Question 18

A patient has a heart murmur due to a leaky mitral valve. Which of the following is a likely consequence?

Accepted Answer

Backflow of blood into the left atrium during ventricular contraction

Question 19

Which nerve provides the primary parasympathetic innervation to the heart?

Accepted Answer

Vagus nerve (cranial nerve X)

Question 20

Which of the following statements about the pulmonary and systemic circuits is correct?

Accepted Answer

The right ventricle pumps deoxygenated blood to the lungs via the pulmonary arteries

Anatomy of the Thorax: The Mediastinum, Heart, and Associated Structures

Study Guide - Practice Questions