HESI A2 Anatomy & Physiology Insight
Series 2025/2026 – 100+ Verified Questions
with Correct Answers | Updated Prep Guide |
A+ Rated
Cardiovascular System
Question 1
Which structure separates the right and left ventricles of the heart?
A. Atrioventricular septum
B. Interventricular septum
C. Coronary sinus
D. Chordae tendineae
Correct Answer: B
Rationale: The interventricular septum is a thick muscular wall that separates the right and left
ventricles, preventing the mixing of oxygen-rich and oxygen-poor blood. The atrioventricular
septum (A) separates atria from ventricles. The coronary sinus (C) is a vein that drains blood
from the heart muscle. Chordae tendineae (D) anchor heart valves.
Question 2
What is the primary function of the pulmonary arteries?
A. Carry oxygenated blood to the lungs
B. Carry deoxygenated blood to the lungs
C. Supply blood to the heart muscle
D. Return oxygenated blood to the heart
Correct Answer: B
Rationale: Pulmonary arteries carry deoxygenated blood from the right ventricle to the lungs for
oxygenation, unlike systemic arteries, which carry oxygenated blood. Option A is incorrect as
pulmonary arteries carry deoxygenated blood. Option C refers to coronary arteries. Option D
describes pulmonary veins.
Question 3
Which blood vessel layer contains smooth muscle to regulate vessel diameter?
A. Tunica intima
,B. Tunica media
C. Tunica externa
D. Endocardium
Correct Answer: B
Rationale: The tunica media, the middle layer of blood vessels, contains smooth muscle that
contracts or relaxes to regulate vessel diameter and blood flow. The tunica intima (A) is the
innermost layer, the tunica externa (C) is the outer layer, and the endocardium (D) lines the
heart’s interior.
Question 4
What is the role of erythrocytes in the cardiovascular system?
A. Fight infection
B. Transport oxygen
C. Clot blood
D. Produce hormones
Correct Answer: B
Rationale: Erythrocytes (red blood cells) contain hemoglobin, which binds and transports
oxygen from the lungs to tissues. Leukocytes (A) fight infection, platelets (C) aid in clotting, and
hormones (D) are produced by endocrine glands.
Question 5
Which valve prevents backflow into the left ventricle during systole?
A. Mitral valve
B. Tricuspid valve
C. Aortic valve
D. Pulmonary valve
Correct Answer: C
Rationale: The aortic valve prevents backflow of blood from the aorta into the left ventricle
during systole (contraction). The mitral valve (A) prevents backflow into the left atrium, the
tricuspid valve (B) into the right atrium, and the pulmonary valve (D) into the right ventricle.
Question 6
What is the pacemaker of the heart?
A. Atrioventricular node
B. Sinoatrial node
C. Purkinje fibers
D. Bundle of His
Correct Answer: B
Rationale: The sinoatrial (SA) node, located in the right atrium, generates electrical impulses to
, initiate heartbeats, acting as the heart’s pacemaker. The AV node (A) relays impulses, while
Purkinje fibers (C) and the Bundle of His (D) conduct impulses to the ventricles.
Question 7
Which component of blood is primarily responsible for clotting?
A. Platelets
B. Plasma
C. Leukocytes
D. Erythrocytes
Correct Answer: A
Rationale: Platelets form clots by adhering to damaged vessel walls and releasing clotting
factors. Plasma (B) is the liquid component, leukocytes (C) fight infection, and erythrocytes (D)
transport oxygen.
Question 8
What is the term for the volume of blood pumped by the heart per minute?
A. Stroke volume
B. Cardiac output
C. Heart rate
D. Ejection fraction
Correct Answer: B
Rationale: Cardiac output is the volume of blood pumped by the heart per minute, calculated as
heart rate × stroke volume. Stroke volume (A) is the blood pumped per beat, heart rate (C) is
beats per minute, and ejection fraction (D) is the percentage of blood pumped per beat.
Question 9
Which blood vessel carries oxygenated blood from the lungs to the heart?
A. Pulmonary artery
B. Pulmonary vein
C. Coronary artery
D. Superior vena cava
Correct Answer: B
Rationale: Pulmonary veins carry oxygenated blood from the lungs to the left atrium. Pulmonary
arteries (A) carry deoxygenated blood to the lungs, coronary arteries (C) supply the heart, and
the superior vena cava (D) returns deoxygenated blood to the heart.
Question 10
What is the primary source of energy for cardiac muscle contraction?
A. Glucose
Series 2025/2026 – 100+ Verified Questions
with Correct Answers | Updated Prep Guide |
A+ Rated
Cardiovascular System
Question 1
Which structure separates the right and left ventricles of the heart?
A. Atrioventricular septum
B. Interventricular septum
C. Coronary sinus
D. Chordae tendineae
Correct Answer: B
Rationale: The interventricular septum is a thick muscular wall that separates the right and left
ventricles, preventing the mixing of oxygen-rich and oxygen-poor blood. The atrioventricular
septum (A) separates atria from ventricles. The coronary sinus (C) is a vein that drains blood
from the heart muscle. Chordae tendineae (D) anchor heart valves.
Question 2
What is the primary function of the pulmonary arteries?
A. Carry oxygenated blood to the lungs
B. Carry deoxygenated blood to the lungs
C. Supply blood to the heart muscle
D. Return oxygenated blood to the heart
Correct Answer: B
Rationale: Pulmonary arteries carry deoxygenated blood from the right ventricle to the lungs for
oxygenation, unlike systemic arteries, which carry oxygenated blood. Option A is incorrect as
pulmonary arteries carry deoxygenated blood. Option C refers to coronary arteries. Option D
describes pulmonary veins.
Question 3
Which blood vessel layer contains smooth muscle to regulate vessel diameter?
A. Tunica intima
,B. Tunica media
C. Tunica externa
D. Endocardium
Correct Answer: B
Rationale: The tunica media, the middle layer of blood vessels, contains smooth muscle that
contracts or relaxes to regulate vessel diameter and blood flow. The tunica intima (A) is the
innermost layer, the tunica externa (C) is the outer layer, and the endocardium (D) lines the
heart’s interior.
Question 4
What is the role of erythrocytes in the cardiovascular system?
A. Fight infection
B. Transport oxygen
C. Clot blood
D. Produce hormones
Correct Answer: B
Rationale: Erythrocytes (red blood cells) contain hemoglobin, which binds and transports
oxygen from the lungs to tissues. Leukocytes (A) fight infection, platelets (C) aid in clotting, and
hormones (D) are produced by endocrine glands.
Question 5
Which valve prevents backflow into the left ventricle during systole?
A. Mitral valve
B. Tricuspid valve
C. Aortic valve
D. Pulmonary valve
Correct Answer: C
Rationale: The aortic valve prevents backflow of blood from the aorta into the left ventricle
during systole (contraction). The mitral valve (A) prevents backflow into the left atrium, the
tricuspid valve (B) into the right atrium, and the pulmonary valve (D) into the right ventricle.
Question 6
What is the pacemaker of the heart?
A. Atrioventricular node
B. Sinoatrial node
C. Purkinje fibers
D. Bundle of His
Correct Answer: B
Rationale: The sinoatrial (SA) node, located in the right atrium, generates electrical impulses to
, initiate heartbeats, acting as the heart’s pacemaker. The AV node (A) relays impulses, while
Purkinje fibers (C) and the Bundle of His (D) conduct impulses to the ventricles.
Question 7
Which component of blood is primarily responsible for clotting?
A. Platelets
B. Plasma
C. Leukocytes
D. Erythrocytes
Correct Answer: A
Rationale: Platelets form clots by adhering to damaged vessel walls and releasing clotting
factors. Plasma (B) is the liquid component, leukocytes (C) fight infection, and erythrocytes (D)
transport oxygen.
Question 8
What is the term for the volume of blood pumped by the heart per minute?
A. Stroke volume
B. Cardiac output
C. Heart rate
D. Ejection fraction
Correct Answer: B
Rationale: Cardiac output is the volume of blood pumped by the heart per minute, calculated as
heart rate × stroke volume. Stroke volume (A) is the blood pumped per beat, heart rate (C) is
beats per minute, and ejection fraction (D) is the percentage of blood pumped per beat.
Question 9
Which blood vessel carries oxygenated blood from the lungs to the heart?
A. Pulmonary artery
B. Pulmonary vein
C. Coronary artery
D. Superior vena cava
Correct Answer: B
Rationale: Pulmonary veins carry oxygenated blood from the lungs to the left atrium. Pulmonary
arteries (A) carry deoxygenated blood to the lungs, coronary arteries (C) supply the heart, and
the superior vena cava (D) returns deoxygenated blood to the heart.
Question 10
What is the primary source of energy for cardiac muscle contraction?
A. Glucose
