BIOD 152 Module 4: Cardiovascular System Exam 2026/2027 UPDATE
1. Which layer of the heart wall is composed primarily of cardiac muscle tissue?
A. Epicardium
B. Pericardium
C. Endocardium
D. Myocardium
Answer: D
Rationale: The myocardium is the thick middle layer of the heart wall consisting of cardiac
muscle cells responsible for pumping blood.
2. The tricuspid valve prevents the backflow of blood from the:
A. Left ventricle to the left atrium
B. Right ventricle to the right atrium
C. Pulmonary trunk to the right ventricle
D. Aorta to the left ventricle
Answer: B
Rationale: The tricuspid valve is an atrioventricular valve located between the right
atrium and the right ventricle.
3. Which part of the conduction system is known as the ‘natural pacemaker’ of
the heart?
A. AV node
B. Bundle of His
C. SA node
D. Purkinje fibers
Answer: C
,Rationale: The sinoatrial (SA) node initiates the electrical impulse that sets the pace for
the heart rate.
4. What does the P wave represent on an EKG?
A. Ventricular depolarization
B. Atrial repolarization
C. Atrial depolarization
D. Ventricular repolarization
Answer: C
Rationale: The P wave represents the electrical activity associated with the depolarization
of the atria.
5. Which of the following blood types is considered the ‘universal donor’?
A. O negative
B. O positive
C. AB positive
D. AB negative
Answer: A
Rationale: O negative blood lacks A, B, and Rh antigens, making it safe for transfusion into
patients with any other blood type.
6. The ‘lub’ sound (S1) of the heart is caused by the:
A. Closing of the semilunar valves
B. Closing of the atrioventricular valves
C. Opening of the semilunar valves
D. Opening of the atrioventricular valves
Answer: B
Rationale: The first heart sound (S1) occurs when the AV valves (mitral and tricuspid)
close at the start of ventricular systole.
, 7. Which hormone, produced by the kidneys, stimulates the production of red
blood cells?
A. Thrombopoietin
B. Cortisol
C. Erythropoietin
D. Aldosterone
Answer: C
Rationale: Erythropoietin (EPO) is released by the kidneys in response to low oxygen
levels to stimulate bone marrow to produce erythrocytes.
8. Which of the following is the correct order of blood flow through the heart?
A. Right Ventricle, Pulmonary Valve, Left Atrium, Tricuspid Valve
B. Left Atrium, Tricuspid Valve, Left Ventricle, Aortic Valve
C. Right Atrium, Mitral Valve, Right Ventricle, Pulmonary Valve
D. Right Atrium, Tricuspid Valve, Right Ventricle, Pulmonary Valve
Answer: D
Rationale: Blood flows from the right atrium through the tricuspid valve into the right
ventricle, then through the pulmonary valve.
9. Cardiac Output is calculated by multiplying:
A. Stroke volume and heart rate
B. Blood pressure and heart rate
C. Stroke volume and peripheral resistance
D. End-diastolic volume and end-systolic volume
Answer: A
Rationale: Cardiac Output (CO) = Stroke Volume (SV) x Heart Rate (HR).
1. Which layer of the heart wall is composed primarily of cardiac muscle tissue?
A. Epicardium
B. Pericardium
C. Endocardium
D. Myocardium
Answer: D
Rationale: The myocardium is the thick middle layer of the heart wall consisting of cardiac
muscle cells responsible for pumping blood.
2. The tricuspid valve prevents the backflow of blood from the:
A. Left ventricle to the left atrium
B. Right ventricle to the right atrium
C. Pulmonary trunk to the right ventricle
D. Aorta to the left ventricle
Answer: B
Rationale: The tricuspid valve is an atrioventricular valve located between the right
atrium and the right ventricle.
3. Which part of the conduction system is known as the ‘natural pacemaker’ of
the heart?
A. AV node
B. Bundle of His
C. SA node
D. Purkinje fibers
Answer: C
,Rationale: The sinoatrial (SA) node initiates the electrical impulse that sets the pace for
the heart rate.
4. What does the P wave represent on an EKG?
A. Ventricular depolarization
B. Atrial repolarization
C. Atrial depolarization
D. Ventricular repolarization
Answer: C
Rationale: The P wave represents the electrical activity associated with the depolarization
of the atria.
5. Which of the following blood types is considered the ‘universal donor’?
A. O negative
B. O positive
C. AB positive
D. AB negative
Answer: A
Rationale: O negative blood lacks A, B, and Rh antigens, making it safe for transfusion into
patients with any other blood type.
6. The ‘lub’ sound (S1) of the heart is caused by the:
A. Closing of the semilunar valves
B. Closing of the atrioventricular valves
C. Opening of the semilunar valves
D. Opening of the atrioventricular valves
Answer: B
Rationale: The first heart sound (S1) occurs when the AV valves (mitral and tricuspid)
close at the start of ventricular systole.
, 7. Which hormone, produced by the kidneys, stimulates the production of red
blood cells?
A. Thrombopoietin
B. Cortisol
C. Erythropoietin
D. Aldosterone
Answer: C
Rationale: Erythropoietin (EPO) is released by the kidneys in response to low oxygen
levels to stimulate bone marrow to produce erythrocytes.
8. Which of the following is the correct order of blood flow through the heart?
A. Right Ventricle, Pulmonary Valve, Left Atrium, Tricuspid Valve
B. Left Atrium, Tricuspid Valve, Left Ventricle, Aortic Valve
C. Right Atrium, Mitral Valve, Right Ventricle, Pulmonary Valve
D. Right Atrium, Tricuspid Valve, Right Ventricle, Pulmonary Valve
Answer: D
Rationale: Blood flows from the right atrium through the tricuspid valve into the right
ventricle, then through the pulmonary valve.
9. Cardiac Output is calculated by multiplying:
A. Stroke volume and heart rate
B. Blood pressure and heart rate
C. Stroke volume and peripheral resistance
D. End-diastolic volume and end-systolic volume
Answer: A
Rationale: Cardiac Output (CO) = Stroke Volume (SV) x Heart Rate (HR).
