B4M2Q2 24-25

Question 1

Gas and nutrient exchange occurs in only one component of the circulatory
system. Which of the following allows such exchange?
A. Pump (heart)
B. Lymphatic system
C. Conduits (blood vessels)
D. Capillary-Endothelial System

Answer 1

D. Capillary-Endothelial System

Question 2

When a patient bleeds, from which part of the circulatory system does the
immediate infusion of volume to increase the circulating volume come from?
A. Heart and Lungs
B. Venules & systemic veins
C. Aorta, arteries and arterioles
D. Pulmonary vessels & capillaries

Answer 2

B. Venules & systemic veins

Question 3

In the earliest phases of septic shock, BP may still be normal despite signs of
hypoperfusion. Which of the following explains this?
A. BP is maintained by increasing SVR that compromises perfusion
B. The cardiac output is inversely related to the Blood Pressure
C. The stroke volume (SV) is augmented by tachycardia
D. Hydrostatic pressure increases during shock stat

Answer 3

A. BP is maintained by increasing SVR that compromises perfusion

Question 4

A 55-year old lineman was electrocuted, suffered 3rd degree burns over 60% of
his body with massive loss of protein-rich exudation. He is admitted with BP 90/50. Which of the following processes will ensue?
A. The heart rate will increase
B. The interstitial space will contract
C. Angiotensinogen production is suppressed
D. The GI tract becomes hyperactive due to hypoperfusi

Answer 4

A. The heart rate will increase

Question 5

How do you interpret the formula: Flow (Q) = Pressure gradient/Resistance
A. The greater the resistance, the more the flow
B. Flow increases as the pressure gradient decreases
C. Decrease in resistance will increase the blood flow
D. Pressure gradient is inversely related to the degree of resistance

Answer 5

C. Decrease in resistance will increase the blood flow

Question 6

The human body is composed of 60 - 75% water. In which of the following is the
majority of this water located?
A. Intravascular space
B. Intracellular space
C. Lymphatic space
D. Interstitial spac

Answer 6

B. Intracellular space

Question 7

After the release of a medical tourniquet, the patient reported that his heart was pounding in his chest. Vital signs were otherwise normal. Which principle explains this?
A. Ohm’s Law
B. Bohr’s law of fluids
C. Starling’s law of the heart
D. Pousseille’s law of blood flo

Answer 7

C. Starling’s law of the heart

Question 8

With a normal cardiac structure and function, the total amount of blood at any
given time is:
A. Greatest in the systemic circulation
B. The same in all parts of the circulatory system
C. Always greatest in the tissue with the fastest metabolism
D. Regulated according to the dictates of the neuro-endocrine system

Answer 8

B. The same in all parts of the circulatory system

Question 9

Which of the following is TRUE of the cardiac cycle?
A. The atria provide the major source of power for moving blood through the
body’s vascular system
B. The ventricles contract ahead of atrial contraction.
C. Each cycle is initiated by spontaneous generation of action potential in the sinus node.
D. Increasing heart rate increases the duration of each cycle.

Answer 9

C. Each cycle is initiated by spontaneous generation of action potential in the sinus node.

Question 10

Which of the following happens during isovolumetric contraction?
a. The second heart sound is produced at this time.
b. There is ventricular contraction but no emptying occurs.
c. It begins right before onset of QRS wave.
d. Ventricular pressure gradually rises.

Answer 10

b. There is ventricular contraction but no emptying occurs.

Question 11

Which of the following occurs during rapid ventricular ejection?
a. There is maximum increase in ventricular pressure.
b. Opening of the aortic valve is caused by high aortic pressure.
c. The onset of T wave marks the beginning of the contraction.
d. Ventricular volume is unchanged

Answer 11

a. There is maximum increase in ventricular pressure.

Question 12

What happens during the isovolumetric contraction of the ventricles?
a. It begins at the period of when blood starts to fill the ventricles.
b. The ventricles are half filled at 120ml.
c. With excitation, the ventricles contract but maintain its pressure.
d. When all valves are closed, no more blood can be ejected from the ventricle.

Answer 12

d. When all valves are closed, no more blood can be ejected from the ventricle.

Question 13

Which of the following characteristic waves is the record of jugular pressure that
represents atrial systole?
a. a wave
b. b wave
c. c wave
d. v wave

Answer 13

a. a wave

Question 14

Which of the following features tell us about atrial systole of the cardiac cycle?
a. Repolarization of the ventricle is complete
b. Atrial systole is preceded by the p wave
c. Ventricular filling continues but at a slower rate
d. Atrial systole causes the second heart soun

Answer 14

b. Atrial systole is preceded by the p wave

Question 15

Which pressure in the left ventricle can push the semilunar valves open?
a. >60mmHg
b. >70mmHg
c. >80mmHg
d. >90mmHg

Answer 15

c. >80mmHg

Question 16

In which of the following areas is the second heart sound (S2) loudest?
A. Cardiac apex
B. Precordium
C. Lower left sternal border
D. Base of the heart

Answer 16

D. Base of the heart

Question 17

Which of the following best describes S3?
A. It occurs during rapid ventricular filling phase of diastole
B. It is associated with premature closure of the aortic and pulmonic valves
C. It is a high- pitched sound that precedes S2
D. It is a low pitched sound heard one-third through systo

Answer 17

A. It occurs during rapid ventricular filling phase of diastole

Question 18

Which component of S2 occurs first and why?
A. P2 because it occurs immediately after the closure of the mitral valve
B. A2 because the left ventricle finishes systole first
C. P2 because of higher compliance in the pulmonary circulation
D. A2 because of the higher pressures in the aorta

Answer 18

D. A2 because of the higher pressures in the aorta

Question 19

A patient with heart failure presents with an S3 and S4 sound. Which of the
following could be a recommended treatment plan for improving heart function?
A. Diuretic therapy to reduce preload
B. Calcium channel blockers to relax the ventricles
C. Increased fluid intake to reduce heart strain
D. Beta- blockers to slow heart rate and reduce systolic pressure

Answer 19

A. Diuretic therapy to reduce preload

Question 20

Which receptor is primarily involved in the inotropic effect of catecholamines on
the heart?
A. Alpha-1 adrenergic receptor
B. Beta-1 adrenergic receptor
C. Muscarinic receptor
D. Nicotinic receptor

Answer 20

B. Beta-1 adrenergic receptor

Question 21

How does the action of cardiac glycosides affect the calcium cycle in myocardial
cells?
A. By increasing the sodium gradient across the membrane, promoting
calcium extrusion.
B. By inhibiting the sodium-potassium ATPase, leading to higher intracellular calcium
C. By increasing the activity of the calcium pump in the sarcoplasmic reticulum
D. By decreasing the rate of calcium influx during action potentials

Answer 21

B. By inhibiting the sodium-potassium ATPase, leading to higher intracellular calcium

Question 22

Which of the following is the average cardiac output of a resting, supine man?
A. 3.5 L/min
B. 5.0 L/min
C. 6.5 L/min
D. 7.5 L/min

Answer 22

B. 5.0 L/min

Question 23

Which of the following is the term for the amount of blood pumped out of each
ventricle per beat?
A. End-diastolic volume
B. Stroke volume
C. Ejection fraction
D. Cardiac index

Answer 23

B. Stroke volume

Question 24

Which is the approximate ejection fraction of the heart in a healthy individual?
A. 40%
B. 50%
C. 60%
D. 70%

Answer 24

C. 60%

Question 25

Which factor primarily controls the heart rate? A. Blood pressure B. Autonomic Nervous System C. Oxygen levels D. Stroke volume

Answer 25

B. Autonomic Nervous System

Question 26

Which action occurs during the isovolumetric contraction phase of the ventricular pressure-volume loop? A. Blood is ejected from the ventricle B. The ventricular muscle is relaxed C. Ventricular pressure increases while the volume remains constant D. The mitral valve opens for ventricular filling

Answer 26

C. Ventricular pressure increases while the volume remains constant

Question 27

In the Frank-Starling mechanism, which of the following happens as the end- diastolic volume increases? A. The heart rate decreases B. The force of contraction decreases C. The stroke volume increases D. The afterload increases

Answer 27

C. The stroke volume increases

Question 28

Which of the following components of the vascular system have the largest total cross-sectional and surface area? A. Arteries B. Capillaries C. Veins D. Arterioles

Answer 28

B. Capillaries

Question 29

Among the components of the vascular system, which pf the following exhibit the highest resistance? A. Arteries B. Capillaries C. Veins D. Arterioles

Answer 29

D. Arterioles

Question 30

Which of the following are expected to contain the highest proportion of blood in the cardiovascular system? A. Arteries B. Capillaries C. Veins D. Arterioles

Answer 30

C. Veins

Question 31

The diameter of arterioles is said to be less than: A. 0.1 cm B. 0.1 mm C. 0.5 cm D. 0.5 mm

Answer 31

B. 0.1 mm

Question 32

Which of the following is TRUE of the site of exchange of nutrients, water and gases? A. They have the largest total cross-sectional and surface area. B. They exhibit the highest resistance in the cardiovascular system. C. They contain the highest proportion of blood in the vascular system. D. They are thick-walled and exhibit high pressure

Answer 32

A. They have the largest total cross-sectional and surface area.

Question 33

Which is the innermost layer of blood vessels? a. Tunica intima b. Tunica media c. Tunica externa d. Endothelium

Answer 33

a. Tunica intima

Question 34

Which layer of blood vessels is responsible for regulating blood flow and pressure? a. Tunica intima b. Tunica media c. Tunica externa d. Endothelium

Answer 34

b. Tunica media

Question 35

Which type of blood vessel has the thickest tunica externa? a. Artery b. Vein c. Capillary d. Venule

Answer 35

b. Vein

Question 36

Which blood vessel type has valves to prevent the backflow of blood? a. Artery b. Vein c. Capillary d. Venule

Answer 36

b. Vein

Question 37

Which is the function of smooth muscle in the tunica media of blood vessels? a. Nutrient exchange b. Regulation of blood flow and pressure c. Oxygen transport d. Waste removal

Answer 37

b. Regulation of blood flow and pressure

Question 38

Which blood vessel type has the thinnest walls and is responsible for nutrient and gas exchange? a. Artery b. Vein c. Capillary d. Venule

Answer 38

c. Capillary

Question 39

A patient presents with symptoms of hypertension. Which histologic feature of blood vessels is most likely to be affected in this condition? a. Thick tunica intima b. Thin tunica media c. Weak tunica externa d. Disrupted endothelium

Answer 39

d. Disrupted endothelium

Question 40

How is capacitance defined in the context of blood vessels? A. The ability of a blood vessel to contract and relax in response to changes in pressure B. The ability of a blood vessel to store and release blood in response to changes in pressure C. The ability of blood vessels to regulate blood flow through vasoconstriction and vasodilation D. The maximum amount of blood a blood vessel can carry at any given time

Answer 40

B. The ability of a blood vessel to store and release blood in response to changes in pressure

Question 41

Which type of blood vessel has the highest capacitance? A. Arteries B. Arterioles C. Capillaries D. Veins

Answer 41

D. Veins

Question 42

Which of the following explains why the blood flow velocity is lowest in the capillaries? A. Capillaries are designed to slow down blood for nutrient exchange B. Capillaries have the smallest diameter, which reduces flow velocity C. Blood is diverted to capillaries from larger vessel, causing slower movement D. Capillaries have higher resistance compared to arteries

Answer 42

A. Capillaries are designed to slow down blood for nutrient exchange

Question 43

Considering the formula for blood flow velocity, what happens to the blood flow velocity as blood moves from large arteries to the capillaries? A. It increases B. It remains constant C. It decreases D. It is fluctuating

Answer 43

C. It decreases

Question 44

Cardiac output (CO) is commonly expressed as: A. CO = stroke volume x heart rate B. CO = mean arterial pressure x total peripheral resistance C. CO = hear rate x blood pressure D. CO = stroke volume + heart rate

Answer 44

A. CO = stroke volume x heart rate

Question 45

Which of the following explains why the greatest pressure decrease in the circulation occurs across the arterioles? A. They have the greatest surface area B. The have the greatest cross-sectional area C. The velocity of blood flow through them is the lowest D. They have the greatest resistance

Answer 45

D. They have the greatest resistance

Question 46

During exercise, blood flow distribution changes to meet the body’s increased metabolic demands. Which of the following correctly describes the relative changes in blood flow to various organs during moderate to intense exercise? A. Increased blood flow to skeletal muscles and skin; decreased blood flow to the heart, brain, and abdominal viscera. B. Increased blood flow to the heart, skeletal muscles, and skin; decreased blood flow to the abdominal viscera; no significant change in brain blood flow. C. Decreased blood flow to skeletal muscles and the brain; increased blood flow to the heart, skin, and abdominal viscera. D. No significant change in blood flow to any organs; total cardiac output remains constant

Answer 46

B. Increased blood flow to the heart, skeletal muscles, and skin; decreased blood flow to the abdominal viscera; no significant change in brain blood flow.

Question 47

During a marathon, a runner experiences increased blood flow to her leg muscles. This is primarily due to: A. Increased sympathetic vasoconstriction B. Accumulation of metabolic byproducts such as carbon dioxide, adenosine and hydrogen ions C. Myogenic constriction of blood vessels D. Reduced cardiac outpu

Answer 47

B. Accumulation of metabolic byproducts such as carbon dioxide, adenosine and hydrogen ions

Question 48

Which of the following best describes the neural mechanism of blood flow regulation? A. Local metabolic byproducts cause vasodilation. B. Sympathetic nervous system activation induces vasoconstriction in most organs. C. Endothelial cells release nitric oxide to regulate vessel diameter. D. Myogenic responses adjust vessel diameter based on blood pressure changes.

Answer 48

B. Sympathetic nervous system activation induces vasoconstriction in most organs.

Question 49

A 45-year-old man suddenly stands up after sitting for an extended period. He briefly feels dizzy before regaining stability. His body compensates for the drop in blood pressure by activating which mechanism? A. Increased parasympathetic stimulation causing vasodilation B. Sympathetic activation causing vasoconstriction in the lower body C. Myogenic vasodilation in the cerebral arteries D. Increased nitric oxide release causing widespread vasodilat

Answer 49

B. Sympathetic activation causing vasoconstriction in the lower body

Question 50

During exercise, which metabolic factor plays a major role in increasing blood flow to skeletal muscles? A. Increased oxygen levels B. Decreased carbon dioxide levels C. Increased adenosine and hydrogen ions D. Increased sympathetic vasoconstriction

Answer 50

C. Increased adenosine and hydrogen ions