NR507 Advanced Pathophysiology Comprehensive Exam Review |
High-Yield Study Guide | 70+ Practice Questions, Verified Answers &
Detailed Rationales
1. What is systole?
Answer: Contraction of the heart muscle, which pumps blood out of the chambers.
Rationale: Systole is the phase of the cardiac cycle when the heart muscle contracts.
Ventricular systole specifically ejects blood into the pulmonary artery and aorta.
2. What produces the S1 and S2 heart sounds?
• Answer: The closing of the heart valves.
• Rationale: Heart sounds are audible vibrations caused by the closure of the heart valves. S1 and
S2 are the classic "lub-dub" sounds, which are not the sounds of the valves opening, but rather
the sounds of them snapping shut.
3. How does blood flow through the heart?
• Answer: Deoxygenated venous blood → Superior Vena Cava → Right Atrium →
Tricuspid Valve → Right Ventricle → Pulmonary Valve → Pulmonary Artery → Lungs
(for oxygenation) → Pulmonary Veins → Left Atrium → Mitral Valve → Left Ventricle
→ Aortic Valve → Aorta → Body.
• Rationale: This is the correct sequence of blood flow through the heart and pulmonary
circulation. The right side of the heart pumps deoxygenated blood to the lungs, and the
left side pumps oxygenated blood to the rest of the body. The valves (Tricuspid,
Pulmonary, Mitral, Aortic) ensure one-way flow.
4. What produces the S1 sound?
• Answer: The closing of the mitral and tricuspid valves (the atrioventricular or AV valves) at the
beginning of systole.
• Rationale: The AV valves close just as the ventricles begin to contract (systole) to prevent blood
from flowing back into the atria. This closure creates the "lub" sound (S1).
5. What is diastole?
• Answer: Relaxation of the heart muscle, allowing the chambers to fill with blood.
• Rationale: Diastole is the phase when the heart muscle relaxes. During ventricular
diastole, the ventricles fill with blood from the atria.
, 5. What produces the S2 sound?
• Answer: The closing of the aortic and pulmonic valves (the semilunar valves) at the beginning
of diastole.
• Rationale: The semilunar valves close just as the ventricles begin to relax (diastole) to prevent
blood from flowing back into the ventricles from the aorta and pulmonary artery. This closure
creates the "dub" sound (S2).
7. What is cardiac output (CO)?
• Answer: The volume of blood pumped out by each ventricle per minute.
• Rationale: Cardiac output is a measure of overall cardiac function and reflects how much blood
the heart is delivering to the body's tissues over time.
8. What is stroke volume (SV)?
• Answer: The amount of blood pumped out by each ventricle with each contraction (or beat).
• Rationale: Stroke volume is the volume of blood ejected per heartbeat. It is a key component of
cardiac output.
9. What determines cardiac output?
• Answer: Stroke volume and heart rate. (CO = SV x HR).
• Rationale: Cardiac output is the product of how much blood is pumped per beat (SV) and how
many beats occur per minute (HR). An increase in either one will generally increase CO,
assuming the other remains constant.
10. What is afterload?
• Answer: The resistance the left ventricle must overcome to eject blood and circulate it
throughout the body.
• Rationale: Afterload is essentially the pressure the heart has to pump against. The higher the
pressure in the aorta, the harder the left ventricle has to work to open the aortic valve and push
blood out.
11. What is contractility?
• Answer: The inherent ability of the heart muscle to contract with a given force for a given
stretch. It is independent of preload and afterload.
• Rationale: Contractility refers to the strength of the heart's contraction at a given fiber length. It
is influenced by factors like sympathetic nervous system stimulation and certain medications, but
is distinct from the stretch-related effects of preload.
, 12. What is preload?
• Answer: The degree of stretch on the heart muscle fibers just before they contract (at
end-diastole). It is related to ventricular filling, end-diastolic pressure, and the amount of
blood entering the ventricle during diastole.
• Rationale: Preload represents the volume of blood returning to the heart. The more blood
that fills the ventricle, the more the muscle fibers are stretched, which influences the
force of the next contraction (Frank-Starling Law).
13. Will sustained tachycardia result in increased or decreased stroke volume?
• Answer: Decreased.
• Rationale: A very fast heart rate (tachycardia) shortens the time for ventricular filling (diastole).
With less time to fill, the ventricles have less blood to pump out, leading to a decrease in stroke
volume.
14. What conditions can result in decreased contractility?
• Answer: Ischemia (lack of oxygen to the heart muscle), acidosis (increased acidity in the blood),
and cardiomyopathy (disease of the heart muscle).
• Rationale: These conditions directly impair the ability of the cardiac muscle fibers to generate
force, reducing the heart's pumping efficiency regardless of preload or afterload.
15. What can cause increased afterload?
• Answer: Hypertension (HTN), pulmonary disease, and damage to the aortic valve.
• Rationale: These conditions increase the resistance the left ventricle faces. Pulmonary disease
can increase pulmonary vascular resistance, affecting the right ventricle. Aortic stenosis (damage
to the aortic valve) creates a physical obstruction that the left ventricle must overcome.
16. What has the most immediate effect on afterload?
• Answer: Hypertension (HTN).
• Rationale: HTN directly and continuously increases systemic vascular resistance, which is the
primary component of afterload for the left ventricle. Changes in HTN will have a quick and
significant impact on the pressure the heart pumps against.
17. Why would hemorrhaging cause decreased afterload?
• Answer: Decreased volume of blood creates less resistance in the blood vessels.
High-Yield Study Guide | 70+ Practice Questions, Verified Answers &
Detailed Rationales
1. What is systole?
Answer: Contraction of the heart muscle, which pumps blood out of the chambers.
Rationale: Systole is the phase of the cardiac cycle when the heart muscle contracts.
Ventricular systole specifically ejects blood into the pulmonary artery and aorta.
2. What produces the S1 and S2 heart sounds?
• Answer: The closing of the heart valves.
• Rationale: Heart sounds are audible vibrations caused by the closure of the heart valves. S1 and
S2 are the classic "lub-dub" sounds, which are not the sounds of the valves opening, but rather
the sounds of them snapping shut.
3. How does blood flow through the heart?
• Answer: Deoxygenated venous blood → Superior Vena Cava → Right Atrium →
Tricuspid Valve → Right Ventricle → Pulmonary Valve → Pulmonary Artery → Lungs
(for oxygenation) → Pulmonary Veins → Left Atrium → Mitral Valve → Left Ventricle
→ Aortic Valve → Aorta → Body.
• Rationale: This is the correct sequence of blood flow through the heart and pulmonary
circulation. The right side of the heart pumps deoxygenated blood to the lungs, and the
left side pumps oxygenated blood to the rest of the body. The valves (Tricuspid,
Pulmonary, Mitral, Aortic) ensure one-way flow.
4. What produces the S1 sound?
• Answer: The closing of the mitral and tricuspid valves (the atrioventricular or AV valves) at the
beginning of systole.
• Rationale: The AV valves close just as the ventricles begin to contract (systole) to prevent blood
from flowing back into the atria. This closure creates the "lub" sound (S1).
5. What is diastole?
• Answer: Relaxation of the heart muscle, allowing the chambers to fill with blood.
• Rationale: Diastole is the phase when the heart muscle relaxes. During ventricular
diastole, the ventricles fill with blood from the atria.
, 5. What produces the S2 sound?
• Answer: The closing of the aortic and pulmonic valves (the semilunar valves) at the beginning
of diastole.
• Rationale: The semilunar valves close just as the ventricles begin to relax (diastole) to prevent
blood from flowing back into the ventricles from the aorta and pulmonary artery. This closure
creates the "dub" sound (S2).
7. What is cardiac output (CO)?
• Answer: The volume of blood pumped out by each ventricle per minute.
• Rationale: Cardiac output is a measure of overall cardiac function and reflects how much blood
the heart is delivering to the body's tissues over time.
8. What is stroke volume (SV)?
• Answer: The amount of blood pumped out by each ventricle with each contraction (or beat).
• Rationale: Stroke volume is the volume of blood ejected per heartbeat. It is a key component of
cardiac output.
9. What determines cardiac output?
• Answer: Stroke volume and heart rate. (CO = SV x HR).
• Rationale: Cardiac output is the product of how much blood is pumped per beat (SV) and how
many beats occur per minute (HR). An increase in either one will generally increase CO,
assuming the other remains constant.
10. What is afterload?
• Answer: The resistance the left ventricle must overcome to eject blood and circulate it
throughout the body.
• Rationale: Afterload is essentially the pressure the heart has to pump against. The higher the
pressure in the aorta, the harder the left ventricle has to work to open the aortic valve and push
blood out.
11. What is contractility?
• Answer: The inherent ability of the heart muscle to contract with a given force for a given
stretch. It is independent of preload and afterload.
• Rationale: Contractility refers to the strength of the heart's contraction at a given fiber length. It
is influenced by factors like sympathetic nervous system stimulation and certain medications, but
is distinct from the stretch-related effects of preload.
, 12. What is preload?
• Answer: The degree of stretch on the heart muscle fibers just before they contract (at
end-diastole). It is related to ventricular filling, end-diastolic pressure, and the amount of
blood entering the ventricle during diastole.
• Rationale: Preload represents the volume of blood returning to the heart. The more blood
that fills the ventricle, the more the muscle fibers are stretched, which influences the
force of the next contraction (Frank-Starling Law).
13. Will sustained tachycardia result in increased or decreased stroke volume?
• Answer: Decreased.
• Rationale: A very fast heart rate (tachycardia) shortens the time for ventricular filling (diastole).
With less time to fill, the ventricles have less blood to pump out, leading to a decrease in stroke
volume.
14. What conditions can result in decreased contractility?
• Answer: Ischemia (lack of oxygen to the heart muscle), acidosis (increased acidity in the blood),
and cardiomyopathy (disease of the heart muscle).
• Rationale: These conditions directly impair the ability of the cardiac muscle fibers to generate
force, reducing the heart's pumping efficiency regardless of preload or afterload.
15. What can cause increased afterload?
• Answer: Hypertension (HTN), pulmonary disease, and damage to the aortic valve.
• Rationale: These conditions increase the resistance the left ventricle faces. Pulmonary disease
can increase pulmonary vascular resistance, affecting the right ventricle. Aortic stenosis (damage
to the aortic valve) creates a physical obstruction that the left ventricle must overcome.
16. What has the most immediate effect on afterload?
• Answer: Hypertension (HTN).
• Rationale: HTN directly and continuously increases systemic vascular resistance, which is the
primary component of afterload for the left ventricle. Changes in HTN will have a quick and
significant impact on the pressure the heart pumps against.
17. Why would hemorrhaging cause decreased afterload?
• Answer: Decreased volume of blood creates less resistance in the blood vessels.
