BIOD 152 LAB 3: CARDIOVASCULAR
SYSTEM - ANATOMY AND HISTOLOGY
OF THE HEART QUESTIONS AND
ANSWERS (VERIFIED ANSWERS)
1. Which layer of the heart wall is synonymous with the visceral layer of the serous
pericardium?
A. Endocardium
B. Myocardium
C. Parietal pericardium
D. Epicardium
Answer: D
Conceptual Explanation: The epicardium is the outermost layer of the heart wall and is
also the visceral layer of the serous pericardium.
2. Which chamber of the heart possesses the thickest myocardium to support high-pressure
systemic circulation?
A. Left Ventricle
B. Right Ventricle
C. Left Atrium
,D. Right Atrium
Answer: A
Conceptual Explanation: The left ventricle must pump blood throughout the entire
systemic circuit, requiring significantly more pressure and muscle mass than the other
chambers.
3. The ‘lub’ sound (S1) of the heart is primarily caused by which event?
A. Closure of the semilunar valves
B. Opening of the atrioventricular valves
C. Closure of the atrioventricular valves
D. Opening of the semilunar valves
Answer: C
Conceptual Explanation: The first heart sound (S1) occurs during ventricular systole
when the tricuspid and bicuspid valves close to prevent backflow into the atria.
4. What is the function of the chordae tendineae?
A. To initiate the electrical signal for ventricular contraction
B. To pull the semilunar valves open during systole
C. To contract and pump blood into the aorta
D. To anchor the AV valve flaps and prevent eversion into the atria
, Answer: D
Conceptual Explanation: Chordae tendineae, or ‘heart strings,’ work with papillary
muscles to prevent the atrioventricular valves from flipping backward into the atria during
ventricular contraction.
5. Which structure in the cardiac conduction system is known as the ‘pacemaker’ because it
sets the sinus rhythm?
A. Sinoatrial (SA) Node
B. AV Bundle (Bundle of His)
C. Atrioventricular (AV) Node
D. Purkinje Fibers
Answer: A
Conceptual Explanation: The SA node, located in the right atrium, typically has the fastest
rate of spontaneous depolarization, determining the heart rate.
6. In an Electrocardiogram (ECG), the P wave represents which physiological event?
A. Ventricular depolarization
B. Atrial repolarization
C. Atrial depolarization
D. Ventricular repolarization
Answer: C
SYSTEM - ANATOMY AND HISTOLOGY
OF THE HEART QUESTIONS AND
ANSWERS (VERIFIED ANSWERS)
1. Which layer of the heart wall is synonymous with the visceral layer of the serous
pericardium?
A. Endocardium
B. Myocardium
C. Parietal pericardium
D. Epicardium
Answer: D
Conceptual Explanation: The epicardium is the outermost layer of the heart wall and is
also the visceral layer of the serous pericardium.
2. Which chamber of the heart possesses the thickest myocardium to support high-pressure
systemic circulation?
A. Left Ventricle
B. Right Ventricle
C. Left Atrium
,D. Right Atrium
Answer: A
Conceptual Explanation: The left ventricle must pump blood throughout the entire
systemic circuit, requiring significantly more pressure and muscle mass than the other
chambers.
3. The ‘lub’ sound (S1) of the heart is primarily caused by which event?
A. Closure of the semilunar valves
B. Opening of the atrioventricular valves
C. Closure of the atrioventricular valves
D. Opening of the semilunar valves
Answer: C
Conceptual Explanation: The first heart sound (S1) occurs during ventricular systole
when the tricuspid and bicuspid valves close to prevent backflow into the atria.
4. What is the function of the chordae tendineae?
A. To initiate the electrical signal for ventricular contraction
B. To pull the semilunar valves open during systole
C. To contract and pump blood into the aorta
D. To anchor the AV valve flaps and prevent eversion into the atria
, Answer: D
Conceptual Explanation: Chordae tendineae, or ‘heart strings,’ work with papillary
muscles to prevent the atrioventricular valves from flipping backward into the atria during
ventricular contraction.
5. Which structure in the cardiac conduction system is known as the ‘pacemaker’ because it
sets the sinus rhythm?
A. Sinoatrial (SA) Node
B. AV Bundle (Bundle of His)
C. Atrioventricular (AV) Node
D. Purkinje Fibers
Answer: A
Conceptual Explanation: The SA node, located in the right atrium, typically has the fastest
rate of spontaneous depolarization, determining the heart rate.
6. In an Electrocardiogram (ECG), the P wave represents which physiological event?
A. Ventricular depolarization
B. Atrial repolarization
C. Atrial depolarization
D. Ventricular repolarization
Answer: C
