Question 1

Which of the following best describes the primary function of elastic (conducting) arteries in the cardiovascular system?

Accepted Answer

They serve as pressure reservoirs that help maintain blood flow during ventricular diastole.

Question 2

According to Poiseuille’s Law, which change would result in the greatest increase in blood flow through a vessel?

Accepted Answer

Doubling the radius of the vessel.

Question 3

A patient has a blood pressure of 120/80 mmHg. What is their mean arterial pressure (MAP) using the formula $$MAP = 	ext{diastolic} + \frac{	ext{pulse pressure}}{3}$$?

Accepted Answer

$$MAP = 80 + \frac{40}{3} = 93.3$$ mmHg

Question 4

Which of the following capillary types is most likely to be found in the liver and bone marrow, and why?

Accepted Answer

Sinusoidal capillaries, because they have large gaps and are the most permeable.

Question 5

If the radius of an arteriole is reduced by half, what happens to the resistance to blood flow, according to Poiseuille’s Law ($$R = \frac{8L\eta}{\pi r^4$}$$)?

Accepted Answer

Resistance increases by a factor of 16.

Question 6

Which mechanism is primarily responsible for the short-term regulation of blood pressure in response to standing up quickly?

Accepted Answer

Baroreceptor reflex increasing sympathetic nervous system activity.

Question 7

A patient is given a drug that blocks β2-adrenergic receptors. What is the most likely effect on blood flow to skeletal muscle during exercise?

Accepted Answer

Decreased vasodilation and decreased blood flow.

Question 8

Which of the following best explains why velocity of blood flow is lowest in the capillaries?

Accepted Answer

Capillaries have the highest total cross-sectional area.

Question 9

Which of the following would most likely cause a decrease in mean arterial pressure (MAP)?

Accepted Answer

Widespread vasodilation of arterioles.

Question 10

A patient with liver failure has reduced plasma albumin levels. What effect does this have on capillary exchange?

Accepted Answer

Decreased capillary osmotic pressure, leading to more filtration and edema.

Question 11

Which of the following statements about veins is correct?

Accepted Answer

Veins contain valves to prevent backflow and act as blood reservoirs.

Question 12

During exercise, local metabolites such as $$CO_2$$ and $$H^+$$ accumulate in skeletal muscle. What is the effect on arterioles supplying these muscles?

Accepted Answer

Vasodilation due to local metabolic control.

Question 13

Which of the following best describes the role of precapillary sphincters?

Accepted Answer

They regulate the amount of blood entering capillary beds in response to local conditions.

Question 14

If a person loses a significant amount of blood, which compensatory mechanism is most likely to occur first?

Accepted Answer

Activation of the baroreceptor reflex to increase heart rate and vasoconstriction.

Question 15

Which equation correctly relates blood flow (F), pressure gradient ($$\Delta P$$), and resistance (R)?

Accepted Answer

$$F = \Delta P / R$$

Question 16

Which of the following would most likely increase peripheral resistance and therefore increase mean arterial pressure (MAP)?

Accepted Answer

Increased length of blood vessels.

Question 17

A patient is given intravenous fluids, increasing their blood volume. What is the expected effect on mean arterial pressure (MAP)?

Accepted Answer

MAP will increase due to increased blood volume.

Question 18

Which of the following is a direct effect of norepinephrine released from sympathetic postganglionic neurons on most systemic arterioles?

Accepted Answer

Vasoconstriction via α receptors.

Question 19

Which of the following best explains why systemic veins are called capacitance vessels?

Accepted Answer

They contain the majority of the body's blood volume at rest.

Question 20

Which of the following would most likely occur if the baroreceptors in the carotid sinus are damaged and cannot detect high blood pressure?

Accepted Answer

The medulla would not decrease sympathetic activity, resulting in sustained high blood pressure.

Blood Flow and Pressure: Structure, Function, and Regulation

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