Strayer University SCI 221 Anatomy and Physiology II Exam 2 (pdf) |
2026/2027 | A&P II Q&A | Anatomy
1. Which of the following chambers of the heart has the thickest
myocardium?
A) Right atrium
B) Right ventricle
C) Left atrium
D) Left ventricle
Correct Answer: Left ventricle
Rationale: The left ventricle has the thickest myocardium because it must
generate enough force to pump oxygenated blood through the systemic
circulation against high resistance. The right ventricle pumps blood to the
lungs, which requires less force. The atria have thin walls because they only
receive blood and pump it into the ventricles.
2. The pulmonary arteries carry:
A) Oxygenated blood to the lungs
B) Deoxygenated blood to the lungs
C) Oxygenated blood to the body
D) Deoxygenated blood to the body
Correct Answer: Deoxygenated blood to the lungs
Rationale: The pulmonary arteries are unique in that they carry
deoxygenated blood from the right ventricle to the lungs for oxygenation.
The pulmonary veins carry oxygenated blood back to the heart. All other
arteries carry oxygenated blood.
,3. Which of the following valves prevents backflow of blood from the aorta
into the left ventricle?
A) Mitral valve
B) Tricuspid valve
C) Pulmonary valve
D) Aortic valve
Correct Answer: Aortic valve
Rationale: The aortic valve is a semilunar valve located at the entrance of
the aorta. It prevents backflow of blood from the aorta into the left ventricle
during diastole. The pulmonary valve prevents backflow into the right
ventricle, and the atrioventricular valves (mitral and tricuspid) prevent
backflow into the atria.
4. The sinoatrial (SA) node is located in the:
A) Left atrium
B) Right atrium
C) Interventricular septum
D) Left ventricle
Correct Answer: Right atrium
Rationale: The SA node is located in the wall of the right atrium near the
opening of the superior vena cava. It is the heart's primary pacemaker,
initiating the electrical impulses that set the heart rate.
5. Which of the following correctly traces the conduction pathway of the
heart?
,A) SA node → AV node → Bundle of His → Purkinje fibers → Bundle branches
B) SA node → AV node → Bundle of His → Bundle branches → Purkinje fibers
C) AV node → SA node → Bundle of His → Bundle branches → Purkinje fibers
D) SA node → Bundle of His → AV node → Bundle branches → Purkinje fibers
Correct Answer: SA node → AV node → Bundle of His → Bundle branches →
Purkinje fibers
Rationale: The cardiac conduction pathway is: SA node → AV node → Bundle
of His → Bundle branches → Purkinje fibers. The SA node initiates the
impulse, which then travels to the AV node, where it is delayed to allow atrial
contraction to complete before ventricular contraction.
6. The T wave on an electrocardiogram (ECG) represents:
A) Atrial depolarization
B) Ventricular depolarization
C) Ventricular repolarization
D) Atrial repolarization
Correct Answer: Ventricular repolarization
Rationale: The T wave represents ventricular repolarization, which is the
recovery phase of the ventricles. The P wave represents atrial depolarization,
and the QRS complex represents ventricular depolarization.
7. What is the term for the amount of blood pumped by each ventricle per
minute?
A) Stroke volume
B) Cardiac output
, C) Heart rate
D) Ejection fraction
Correct Answer: Cardiac output
Rationale: Cardiac output is the volume of blood pumped by each ventricle
per minute, calculated as stroke volume multiplied by heart rate. Stroke
volume is the amount pumped per beat, and ejection fraction is the
percentage of blood ejected from the ventricle.
8. Which of the following factors directly increases stroke volume?
A) Increased afterload
B) Decreased venous return
C) Increased contractility
D) Increased heart rate
Correct Answer: Increased contractility
Rationale: Increased contractility (positive inotropy) increases stroke volume
by increasing the force of ventricular contraction. Increased afterload
reduces stroke volume, and decreased venous return reduces preload and
stroke volume. Heart rate affects cardiac output but not directly stroke
volume.
9. The first heart sound (S1 or "lub") is caused by:
A) Closing of the semilunar valves
B) Closing of the atrioventricular valves
C) Opening of the atrioventricular valves
D) Opening of the semilunar valves
2026/2027 | A&P II Q&A | Anatomy
1. Which of the following chambers of the heart has the thickest
myocardium?
A) Right atrium
B) Right ventricle
C) Left atrium
D) Left ventricle
Correct Answer: Left ventricle
Rationale: The left ventricle has the thickest myocardium because it must
generate enough force to pump oxygenated blood through the systemic
circulation against high resistance. The right ventricle pumps blood to the
lungs, which requires less force. The atria have thin walls because they only
receive blood and pump it into the ventricles.
2. The pulmonary arteries carry:
A) Oxygenated blood to the lungs
B) Deoxygenated blood to the lungs
C) Oxygenated blood to the body
D) Deoxygenated blood to the body
Correct Answer: Deoxygenated blood to the lungs
Rationale: The pulmonary arteries are unique in that they carry
deoxygenated blood from the right ventricle to the lungs for oxygenation.
The pulmonary veins carry oxygenated blood back to the heart. All other
arteries carry oxygenated blood.
,3. Which of the following valves prevents backflow of blood from the aorta
into the left ventricle?
A) Mitral valve
B) Tricuspid valve
C) Pulmonary valve
D) Aortic valve
Correct Answer: Aortic valve
Rationale: The aortic valve is a semilunar valve located at the entrance of
the aorta. It prevents backflow of blood from the aorta into the left ventricle
during diastole. The pulmonary valve prevents backflow into the right
ventricle, and the atrioventricular valves (mitral and tricuspid) prevent
backflow into the atria.
4. The sinoatrial (SA) node is located in the:
A) Left atrium
B) Right atrium
C) Interventricular septum
D) Left ventricle
Correct Answer: Right atrium
Rationale: The SA node is located in the wall of the right atrium near the
opening of the superior vena cava. It is the heart's primary pacemaker,
initiating the electrical impulses that set the heart rate.
5. Which of the following correctly traces the conduction pathway of the
heart?
,A) SA node → AV node → Bundle of His → Purkinje fibers → Bundle branches
B) SA node → AV node → Bundle of His → Bundle branches → Purkinje fibers
C) AV node → SA node → Bundle of His → Bundle branches → Purkinje fibers
D) SA node → Bundle of His → AV node → Bundle branches → Purkinje fibers
Correct Answer: SA node → AV node → Bundle of His → Bundle branches →
Purkinje fibers
Rationale: The cardiac conduction pathway is: SA node → AV node → Bundle
of His → Bundle branches → Purkinje fibers. The SA node initiates the
impulse, which then travels to the AV node, where it is delayed to allow atrial
contraction to complete before ventricular contraction.
6. The T wave on an electrocardiogram (ECG) represents:
A) Atrial depolarization
B) Ventricular depolarization
C) Ventricular repolarization
D) Atrial repolarization
Correct Answer: Ventricular repolarization
Rationale: The T wave represents ventricular repolarization, which is the
recovery phase of the ventricles. The P wave represents atrial depolarization,
and the QRS complex represents ventricular depolarization.
7. What is the term for the amount of blood pumped by each ventricle per
minute?
A) Stroke volume
B) Cardiac output
, C) Heart rate
D) Ejection fraction
Correct Answer: Cardiac output
Rationale: Cardiac output is the volume of blood pumped by each ventricle
per minute, calculated as stroke volume multiplied by heart rate. Stroke
volume is the amount pumped per beat, and ejection fraction is the
percentage of blood ejected from the ventricle.
8. Which of the following factors directly increases stroke volume?
A) Increased afterload
B) Decreased venous return
C) Increased contractility
D) Increased heart rate
Correct Answer: Increased contractility
Rationale: Increased contractility (positive inotropy) increases stroke volume
by increasing the force of ventricular contraction. Increased afterload
reduces stroke volume, and decreased venous return reduces preload and
stroke volume. Heart rate affects cardiac output but not directly stroke
volume.
9. The first heart sound (S1 or "lub") is caused by:
A) Closing of the semilunar valves
B) Closing of the atrioventricular valves
C) Opening of the atrioventricular valves
D) Opening of the semilunar valves
