BIOS 255 EDAPT Week 2 - Cardiovascular System: Heart Anatomy and
Physiology 2026 Chamberlain College
1. Which layer of the heart wall is primarily composed of cardiac muscle tissue?
A. Endocardium
B. Epicardium
C. Myocardium
D. Pericardium
Answer: C
Rationale: The myocardium is the thick middle layer of the heart wall consisting of cardiac
muscle, responsible for the pumping action.
2. Which valve prevents the backflow of blood from the right ventricle into the
right atrium?
A. Tricuspid valve
B. Mitral valve
C. Aortic valve
D. Pulmonary valve
Answer: A
Rationale: The tricuspid valve is the right atrioventricular (AV) valve that prevents blood
from flowing back into the right atrium during ventricular contraction.
,3. Blood traveling through the pulmonary veins is returning to which chamber of
the heart?
A. Right atrium
B. Right ventricle
C. Left atrium
D. Left ventricle
Answer: C
Rationale: Oxygenated blood from the lungs returns via the pulmonary veins into the left
atrium.
4. What is the natural pacemaker of the heart located in the right atrium?
A. Atrioventricular (AV) node
B. Purkinje fibers
C. Sinoatrial (SA) node
D. Bundle of His
Answer: C
Rationale: The SA node initiates the electrical impulse that sets the rhythm of the heart.
5. On an ECG, the P wave represents which of the following events?
A. Ventricular depolarization
B. Atrial depolarization
C. Atrial repolarization
D. Ventricular repolarization
Answer: B
Rationale: The P wave is the first wave of the ECG cycle and represents the electrical
activation (depolarization) of the atria.
, 6. Which structure anchors the atrioventricular valve cusps to the papillary
muscles?
A. Pectinate muscles
B. Trabeculae carneae
C. Fossa ovalis
D. Chordae tendineae
Answer: D
Rationale: Chordae tendineae, often called ‘heart strings,’ prevent the AV valves from
prolapsing into the atria.
7. The ‘lub’ sound of the heart (S1) is caused by the closure of which valves?
A. Semilunar valves
B. AV valves
C. Aortic and Pulmonary valves
D. Vena cava sphincters
Answer: B
Rationale: S1 occurs at the beginning of ventricular systole when the AV valves (mitral and
tricuspid) close.
8. Which vessel carries deoxygenated blood away from the heart to the lungs?
A. Aorta
B. Pulmonary vein
C. Pulmonary artery
D. Superior vena cava
Answer: C
Rationale: The pulmonary arteries carry oxygen-poor blood from the right ventricle to the
lungs.
Physiology 2026 Chamberlain College
1. Which layer of the heart wall is primarily composed of cardiac muscle tissue?
A. Endocardium
B. Epicardium
C. Myocardium
D. Pericardium
Answer: C
Rationale: The myocardium is the thick middle layer of the heart wall consisting of cardiac
muscle, responsible for the pumping action.
2. Which valve prevents the backflow of blood from the right ventricle into the
right atrium?
A. Tricuspid valve
B. Mitral valve
C. Aortic valve
D. Pulmonary valve
Answer: A
Rationale: The tricuspid valve is the right atrioventricular (AV) valve that prevents blood
from flowing back into the right atrium during ventricular contraction.
,3. Blood traveling through the pulmonary veins is returning to which chamber of
the heart?
A. Right atrium
B. Right ventricle
C. Left atrium
D. Left ventricle
Answer: C
Rationale: Oxygenated blood from the lungs returns via the pulmonary veins into the left
atrium.
4. What is the natural pacemaker of the heart located in the right atrium?
A. Atrioventricular (AV) node
B. Purkinje fibers
C. Sinoatrial (SA) node
D. Bundle of His
Answer: C
Rationale: The SA node initiates the electrical impulse that sets the rhythm of the heart.
5. On an ECG, the P wave represents which of the following events?
A. Ventricular depolarization
B. Atrial depolarization
C. Atrial repolarization
D. Ventricular repolarization
Answer: B
Rationale: The P wave is the first wave of the ECG cycle and represents the electrical
activation (depolarization) of the atria.
, 6. Which structure anchors the atrioventricular valve cusps to the papillary
muscles?
A. Pectinate muscles
B. Trabeculae carneae
C. Fossa ovalis
D. Chordae tendineae
Answer: D
Rationale: Chordae tendineae, often called ‘heart strings,’ prevent the AV valves from
prolapsing into the atria.
7. The ‘lub’ sound of the heart (S1) is caused by the closure of which valves?
A. Semilunar valves
B. AV valves
C. Aortic and Pulmonary valves
D. Vena cava sphincters
Answer: B
Rationale: S1 occurs at the beginning of ventricular systole when the AV valves (mitral and
tricuspid) close.
8. Which vessel carries deoxygenated blood away from the heart to the lungs?
A. Aorta
B. Pulmonary vein
C. Pulmonary artery
D. Superior vena cava
Answer: C
Rationale: The pulmonary arteries carry oxygen-poor blood from the right ventricle to the
lungs.
