A&P 2 MODULE 3 EXAM | PORTAGE LEARNING –
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2026-2027
1. A researcher is studying the structural adaptations of the heart in a patient with chronic
systemic hypertension. Which anatomical layer of the heart wall undergoes the most
significant hypertrophy to compensate for increased afterload?
A. Epicardium
B. Myocardium
C. Endocardium
D. Fibrous pericardium
Answer: B
The myocardium consists of thick cardiac muscle tissue that hypertrophies under chronic high
pressure loads to maintain adequate stroke volume against increased ventricular afterload.
2. During a routine clinical evaluation, a patient's electrocardiogram shows an abnormally
prolonged PR interval. Which part of the cardiac conduction system is experiencing a delay
in electrical impulse transmission?
A. Internodal pathways within the atrial myocardium
B. Atrioventricular (AV) node
C. Bundle of His
D. Purkinje fiber network
Answer: B
The PR interval represents the time required for electrical impulses to travel from the
sinoatrial node through the atria and delay at the AV node before ventricular depolarization.
3. A biomedical engineering student is modeling cardiac cycle pressures. At what specific
point in the cardiac cycle do the semilunar valves open?
A. When ventricular pressure falls below atrial pressure
,B. When ventricular pressure exceeds aortic and pulmonary trunk pressure
C. When intraventricular pressure drops to zero during diastole
D. When atrial pressure exceeds ventricular pressure during passive filling
Answer: B
Semilunar valves open only when ventricular pressure surpasses the arterial pressure in the
aorta and pulmonary trunk, forcing blood out into systemic and pulmonary circulation.
4. A patient presents with a murmur best heard at the second intercostal space on the right
sternal border. Which heart valve is most likely associated with this auscultation finding?
A. Mitral valve
B. Tricuspid valve
C. Aortic valve
D. Pulmonary valve
Answer: C
The aortic valve auscultation point is conventionally located at the second right intercostal
space close to the sternal border.
5. Which histological feature is uniquely characteristic of cardiac muscle tissue compared
to skeletal muscle tissue?
A. Presence of peripheral multi-nucleated cells
B. Presence of intercalated discs containing gap junctions and desmosomes
C. Absence of striations along the myofibrils
D. Voluntary nervous control via somatic motor neurons
Answer: B
Cardiac muscle fibers feature specialized cell junctions called intercalated discs with
desmosomes for structural cohesion and gap junctions for synchronized electrical
propagation.
,6. During the plateau phase of a cardiac ventricular muscle cell action potential, which ion
movement is primarily responsible for maintaining depolarization?
A. Influx of sodium ions through fast voltage-gated channels
B. Influx of calcium ions through slow L-type channels
C. Efflux of potassium ions through rapid rectifying channels
D. Active transport of chloride ions via sodium-potassium pumps
Answer: B
The plateau phase is maintained by a sustained influx of extracellular calcium ions through
slow voltage-gated channels, balancing potassium efflux and prolonging contraction time.
7. A medical diagnostic report notes that a patient has an ejection fraction of 65 percent.
How is ejection fraction calculated clinically?
A. Dividing stroke volume by end-diastolic volume
B. Multiplying heart rate by total peripheral resistance
C. Subtracting end-systolic volume from stroke volume
D. Dividing cardiac output by mean arterial pressure
Answer: A
Ejection fraction is the percentage of blood pumped out of the ventricle with each beat,
calculated as stroke volume divided by end-diastolic volume.
8. Which autonomic nerve stimulation decreases heart rate by releasing acetylcholine onto
muscarinic receptors at the sinoatrial node?
A. Sympathetic cardiac accelerator nerves
B. Parasympathetic vagus nerve
C. Phrenic motor nerve
D. Greater splanchnic nerve
Answer: B
, Parasympathetic innervation via the vagus nerve releases acetylcholine, which hyperpolarizes
pacemaker cells and slows down the spontaneous firing rate of the heart.
9. In an adult human heart, what is the primary function of the chordae tendineae attached
to the atrioventricular valve cusps?
A. To actively pull the valve cusps open during ventricular diastole
B. To prevent the valve cusps from everting into the atria during ventricular systole
C. To generate the primary electrical pacemaker signal for the ventricles
D. To regulate coronary blood flow through the myocardium
Answer: B
Chordae tendineae anchor the AV valve flaps to papillary muscles, preventing them from
blowing backward into the atria when high ventricular pressures develop during systole.
10. A patient is diagnosed with severe left ventricular hypertrophy. According to Frank-
Starling's law of the heart, how does increased ventricular filling typically affect stroke
volume under normal physiological limits?
A. It decreases stroke volume due to myocardial fatigue
B. It increases stroke volume due to optimal actin-myosin overlap
C. It has no measurable effect on stroke volume
D. It causes immediate valve prolapse and regurgitation
Answer: B
Frank-Starling's law states that stroke volume increases in response to an increase in end-
diastolic volume by stretching myocardial fibers to an optimal overlapping length.
11. Which blood vessel layer (tunica) is primarily composed of smooth muscle cells and
elastic fibers responsible for regulating vasomotor tone and blood pressure?
A. Tunica interna (intima)
B. Tunica media
C. Tunica externa (adventitia)
D. Endothelium basement membrane
COMPLETE STUDY GUIDE | PRACTICE QUESTIONS AND
ANSWERS-RATIONALES | EXAM PREP | DOWNLOAD
INSTANT PDF | GUARANTEED PASS || LATEST EXAM
2026-2027
1. A researcher is studying the structural adaptations of the heart in a patient with chronic
systemic hypertension. Which anatomical layer of the heart wall undergoes the most
significant hypertrophy to compensate for increased afterload?
A. Epicardium
B. Myocardium
C. Endocardium
D. Fibrous pericardium
Answer: B
The myocardium consists of thick cardiac muscle tissue that hypertrophies under chronic high
pressure loads to maintain adequate stroke volume against increased ventricular afterload.
2. During a routine clinical evaluation, a patient's electrocardiogram shows an abnormally
prolonged PR interval. Which part of the cardiac conduction system is experiencing a delay
in electrical impulse transmission?
A. Internodal pathways within the atrial myocardium
B. Atrioventricular (AV) node
C. Bundle of His
D. Purkinje fiber network
Answer: B
The PR interval represents the time required for electrical impulses to travel from the
sinoatrial node through the atria and delay at the AV node before ventricular depolarization.
3. A biomedical engineering student is modeling cardiac cycle pressures. At what specific
point in the cardiac cycle do the semilunar valves open?
A. When ventricular pressure falls below atrial pressure
,B. When ventricular pressure exceeds aortic and pulmonary trunk pressure
C. When intraventricular pressure drops to zero during diastole
D. When atrial pressure exceeds ventricular pressure during passive filling
Answer: B
Semilunar valves open only when ventricular pressure surpasses the arterial pressure in the
aorta and pulmonary trunk, forcing blood out into systemic and pulmonary circulation.
4. A patient presents with a murmur best heard at the second intercostal space on the right
sternal border. Which heart valve is most likely associated with this auscultation finding?
A. Mitral valve
B. Tricuspid valve
C. Aortic valve
D. Pulmonary valve
Answer: C
The aortic valve auscultation point is conventionally located at the second right intercostal
space close to the sternal border.
5. Which histological feature is uniquely characteristic of cardiac muscle tissue compared
to skeletal muscle tissue?
A. Presence of peripheral multi-nucleated cells
B. Presence of intercalated discs containing gap junctions and desmosomes
C. Absence of striations along the myofibrils
D. Voluntary nervous control via somatic motor neurons
Answer: B
Cardiac muscle fibers feature specialized cell junctions called intercalated discs with
desmosomes for structural cohesion and gap junctions for synchronized electrical
propagation.
,6. During the plateau phase of a cardiac ventricular muscle cell action potential, which ion
movement is primarily responsible for maintaining depolarization?
A. Influx of sodium ions through fast voltage-gated channels
B. Influx of calcium ions through slow L-type channels
C. Efflux of potassium ions through rapid rectifying channels
D. Active transport of chloride ions via sodium-potassium pumps
Answer: B
The plateau phase is maintained by a sustained influx of extracellular calcium ions through
slow voltage-gated channels, balancing potassium efflux and prolonging contraction time.
7. A medical diagnostic report notes that a patient has an ejection fraction of 65 percent.
How is ejection fraction calculated clinically?
A. Dividing stroke volume by end-diastolic volume
B. Multiplying heart rate by total peripheral resistance
C. Subtracting end-systolic volume from stroke volume
D. Dividing cardiac output by mean arterial pressure
Answer: A
Ejection fraction is the percentage of blood pumped out of the ventricle with each beat,
calculated as stroke volume divided by end-diastolic volume.
8. Which autonomic nerve stimulation decreases heart rate by releasing acetylcholine onto
muscarinic receptors at the sinoatrial node?
A. Sympathetic cardiac accelerator nerves
B. Parasympathetic vagus nerve
C. Phrenic motor nerve
D. Greater splanchnic nerve
Answer: B
, Parasympathetic innervation via the vagus nerve releases acetylcholine, which hyperpolarizes
pacemaker cells and slows down the spontaneous firing rate of the heart.
9. In an adult human heart, what is the primary function of the chordae tendineae attached
to the atrioventricular valve cusps?
A. To actively pull the valve cusps open during ventricular diastole
B. To prevent the valve cusps from everting into the atria during ventricular systole
C. To generate the primary electrical pacemaker signal for the ventricles
D. To regulate coronary blood flow through the myocardium
Answer: B
Chordae tendineae anchor the AV valve flaps to papillary muscles, preventing them from
blowing backward into the atria when high ventricular pressures develop during systole.
10. A patient is diagnosed with severe left ventricular hypertrophy. According to Frank-
Starling's law of the heart, how does increased ventricular filling typically affect stroke
volume under normal physiological limits?
A. It decreases stroke volume due to myocardial fatigue
B. It increases stroke volume due to optimal actin-myosin overlap
C. It has no measurable effect on stroke volume
D. It causes immediate valve prolapse and regurgitation
Answer: B
Frank-Starling's law states that stroke volume increases in response to an increase in end-
diastolic volume by stretching myocardial fibers to an optimal overlapping length.
11. Which blood vessel layer (tunica) is primarily composed of smooth muscle cells and
elastic fibers responsible for regulating vasomotor tone and blood pressure?
A. Tunica interna (intima)
B. Tunica media
C. Tunica externa (adventitia)
D. Endothelium basement membrane
