PHSL 2101 - FINAL EXAM PREPARATION:
COMPREHENSIVE MCQ BANK (1-200)
1. According to the Frank-Starling mechanism, an increase in venous
return directly leads to which of the following?
A) A decrease in cardiac output
B) A decrease in stroke volume
C) An increase in end-diastolic volume
D) A decrease in heart rate
Correct Answer: C
Rationale: The Frank-Starling mechanism states that the heart pumps
out whatever volume it receives. An increase in venous return increases
preload (end-diastolic volume), which stretches the cardiac muscle
fibers, leading to a more forceful contraction and increased stroke
volume.
2. Which of the following is the primary pacemaker of the heart?
A) Atrioventricular (AV) node
B) Bundle of His
C) Sinoatrial (SA) node
D) Purkinje fibers
Correct Answer: C
Rationale: The SA node has the highest rate of spontaneous
depolarization (automaticity) and sets the baseline rhythm for the
heart, overriding the other potential pacemakers.
,3. What is the primary effect of parasympathetic stimulation on the
heart?
A) Increased heart rate
B) Increased contractility
C) Decreased heart rate
D) Increased conduction velocity
Correct Answer: C
Rationale: Parasympathetic (vagal) stimulation releases acetylcholine,
which acts on muscarinic receptors to decrease the firing rate of the SA
node, resulting in bradycardia.
4. Which of the following would NOT increase the movement of fluid
out of capillaries?
A) Increased capillary hydrostatic pressure
B) Decreased plasma oncotic pressure
C) Increased interstitial oncotic pressure
D) Increased plasma oncotic pressure
Correct Answer: D
Rationale: Plasma oncotic pressure (osmotic pressure) pulls fluid into
the capillary. Increasing this pressure would oppose fluid movement out
of the capillary, not promote it.
5. According to the Starling Equation, net filtration pressure is
determined by all of the following EXCEPT:
A) Capillary hydrostatic pressure
B) Interstitial hydrostatic pressure
,C) Plasma oncotic pressure
D) The number and size of pores in the capillary wall
Correct Answer: D
Rationale: The Starling Equation describes the balance of hydrostatic
and oncotic pressures across the capillary membrane. The porosity of
the capillary wall affects permeability but is not a force (pressure) in the
equation itself.
6. A reflex increase in heart rate may be caused by:
A) Baroreceptor unloading
B) Sympathetic stimulation
C) Chemoreceptor activation
D) All of the above
Correct Answer: D
Rationale: Baroreceptor unloading (due to decreased blood pressure),
sympathetic activation, and chemoreceptor stimulation (e.g., hypoxia)
all can trigger reflex tachycardia.
7. The major mechanism controlling the diameter of arteries in the
skin is:
A) Local metabolic factors
B) Myogenic autoregulation
C) Sympathetic nerve activity
D) Parasympathetic nerve activity
Correct Answer: C
Rationale: Skin blood vessels are primarily under sympathetic control.
, Increased sympathetic tone causes vasoconstriction, while decreased
tone allows vasodilation, crucial for thermoregulation.
8. Starling's Law of the Heart means that when ventricular preload is
increased, stroke volume will:
A) Decrease
B) Remain unchanged
C) Increase
D) First increase then decrease
Correct Answer: C
Rationale: Starling's Law states that the force of contraction is
proportional to the initial length of the cardiac muscle fibers. Increased
preload stretches the fibers, leading to a stronger contraction and
increased stroke volume.
9. During which phase of the cardiac cycle are all four heart valves
open?
A) Ventricular systole
B) Ventricular diastole
C) Isovolumic contraction
D) None; all four are normally never open simultaneously
Correct Answer: D
Rationale: The atrioventricular and semilunar valves cannot all be open
at the same time. During filling, AV valves are open and semilunar
valves are closed; during ejection, the opposite occurs.
COMPREHENSIVE MCQ BANK (1-200)
1. According to the Frank-Starling mechanism, an increase in venous
return directly leads to which of the following?
A) A decrease in cardiac output
B) A decrease in stroke volume
C) An increase in end-diastolic volume
D) A decrease in heart rate
Correct Answer: C
Rationale: The Frank-Starling mechanism states that the heart pumps
out whatever volume it receives. An increase in venous return increases
preload (end-diastolic volume), which stretches the cardiac muscle
fibers, leading to a more forceful contraction and increased stroke
volume.
2. Which of the following is the primary pacemaker of the heart?
A) Atrioventricular (AV) node
B) Bundle of His
C) Sinoatrial (SA) node
D) Purkinje fibers
Correct Answer: C
Rationale: The SA node has the highest rate of spontaneous
depolarization (automaticity) and sets the baseline rhythm for the
heart, overriding the other potential pacemakers.
,3. What is the primary effect of parasympathetic stimulation on the
heart?
A) Increased heart rate
B) Increased contractility
C) Decreased heart rate
D) Increased conduction velocity
Correct Answer: C
Rationale: Parasympathetic (vagal) stimulation releases acetylcholine,
which acts on muscarinic receptors to decrease the firing rate of the SA
node, resulting in bradycardia.
4. Which of the following would NOT increase the movement of fluid
out of capillaries?
A) Increased capillary hydrostatic pressure
B) Decreased plasma oncotic pressure
C) Increased interstitial oncotic pressure
D) Increased plasma oncotic pressure
Correct Answer: D
Rationale: Plasma oncotic pressure (osmotic pressure) pulls fluid into
the capillary. Increasing this pressure would oppose fluid movement out
of the capillary, not promote it.
5. According to the Starling Equation, net filtration pressure is
determined by all of the following EXCEPT:
A) Capillary hydrostatic pressure
B) Interstitial hydrostatic pressure
,C) Plasma oncotic pressure
D) The number and size of pores in the capillary wall
Correct Answer: D
Rationale: The Starling Equation describes the balance of hydrostatic
and oncotic pressures across the capillary membrane. The porosity of
the capillary wall affects permeability but is not a force (pressure) in the
equation itself.
6. A reflex increase in heart rate may be caused by:
A) Baroreceptor unloading
B) Sympathetic stimulation
C) Chemoreceptor activation
D) All of the above
Correct Answer: D
Rationale: Baroreceptor unloading (due to decreased blood pressure),
sympathetic activation, and chemoreceptor stimulation (e.g., hypoxia)
all can trigger reflex tachycardia.
7. The major mechanism controlling the diameter of arteries in the
skin is:
A) Local metabolic factors
B) Myogenic autoregulation
C) Sympathetic nerve activity
D) Parasympathetic nerve activity
Correct Answer: C
Rationale: Skin blood vessels are primarily under sympathetic control.
, Increased sympathetic tone causes vasoconstriction, while decreased
tone allows vasodilation, crucial for thermoregulation.
8. Starling's Law of the Heart means that when ventricular preload is
increased, stroke volume will:
A) Decrease
B) Remain unchanged
C) Increase
D) First increase then decrease
Correct Answer: C
Rationale: Starling's Law states that the force of contraction is
proportional to the initial length of the cardiac muscle fibers. Increased
preload stretches the fibers, leading to a stronger contraction and
increased stroke volume.
9. During which phase of the cardiac cycle are all four heart valves
open?
A) Ventricular systole
B) Ventricular diastole
C) Isovolumic contraction
D) None; all four are normally never open simultaneously
Correct Answer: D
Rationale: The atrioventricular and semilunar valves cannot all be open
at the same time. During filling, AV valves are open and semilunar
valves are closed; during ejection, the opposite occurs.
