$$2.9 \times 3.785 = 10.98$$ liters

Question 1

Which layer of the heart wall is responsible for the contractile force that pumps blood throughout the body?

Accepted Answer

Myocardium

Question 2

A patient presents with a heart rate of 50 beats per minute. Which term best describes this condition?

Accepted Answer

Bradycardia

Question 3

Which of the following structures prevents the atrioventricular (AV) valves from inverting during ventricular contraction?

Accepted Answer

Chordae tendineae and papillary muscles

Question 4

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

Accepted Answer

Left atrium

Question 5

Which of the following best describes the function of the moderator band in the right ventricle?

Accepted Answer

It prevents overexpansion of the thin-walled right ventricle.

Question 6

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

Accepted Answer

AV valves closed, semilunar valves open

Question 7

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

Accepted Answer

They are striated, have a single centrally placed nucleus, and are interconnected by intercalated discs.

Question 8

If the heart pumps 2.9 gallons of blood per minute, how many liters does it pump per minute? (1 gallon ≈ 3.785 liters)

Accepted Answer

$$2.9 	imes 3.785 = 10.98$$ liters

Question 9

Which of the following is a function of the cardiac skeleton?

Accepted Answer

It stabilizes the position of cardiac cells and valves, provides elasticity, and isolates atrial from ventricular cells.

Question 10

Which vessel carries oxygen-poor blood from the right ventricle to the lungs?

Accepted Answer

Pulmonary trunk

Question 11

What is the primary function of the pericardial fluid found in the pericardial cavity?

Accepted Answer

To lubricate the heart and reduce friction during contraction

Question 12

Which of the following correctly matches the heart chamber with the type of blood it receives?

Accepted Answer

Left atrium receives oxygenated blood from the pulmonary veins

Question 13

Which of the following best describes the role of gap junctions in cardiac muscle tissue?

Accepted Answer

They allow ions to move directly from one cell to another, enabling a functional syncytium.

Question 14

A blockage in the left anterior interventricular branch of the coronary artery would most directly affect which region of the heart?

Accepted Answer

Left ventricle and interventricular septum

Question 15

Which of the following is TRUE regarding the orientation of the heart in the thoracic cavity?

Accepted Answer

The base is the superior border, and the apex is the inferior portion.

Question 16

Which of the following correctly describes the flow of blood through the heart and lungs?

Accepted Answer

Right atrium → right ventricle → pulmonary trunk → lungs → left atrium → left ventricle → aorta

Question 17

Which of the following is a distinguishing histological feature of cardiac muscle cells?

Accepted Answer

Branching interconnections and intercalated discs

Question 18

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

Accepted Answer

It pumps blood throughout the entire systemic circuit, requiring more force.

Question 19

Which of the following is NOT a function of the cardiac skeleton?

Accepted Answer

Initiates the electrical impulse for contraction

Question 20

If the heart beats 100,000 times per day, what is the average number of beats per minute?

Accepted Answer

$$\frac{100,000}{24 	imes 60} = 69.44$$ beats per minute

Chapter 21: The Cardiovascular System – The Heart (Anatomy & Physiology Study Notes)

Study Guide - Practice Questions