Question 1

Which of the following best explains why blood velocity is lowest in the capillaries, even though individual capillaries have a small diameter?

Accepted Answer

Because the total cross-sectional area of all capillaries combined is much greater than that of the aorta.

Question 2

A patient has a blood pressure reading of 150/95 mmHg at rest. Which of the following is the most likely physiological explanation for this elevated systolic pressure?

Accepted Answer

Increased peripheral resistance due to plaque buildup in the arteries.

Question 3

Which equation correctly represents the relationship between flow rate ($$Q$$), pressure difference ($$\Delta P$$), and resistance ($$R) in $$the cardiovascular system?

Accepted Answer

$$Q = \frac{\Delta P}{R}$$

Question 4

If the radius of a blood vessel is halved, how does this affect the resistance to blood flow, according to the equation $$R \propto \frac{1}{r^4$}$$?

Accepted Answer

Resistance increases by a factor of 16.

Question 5

During exercise, blood flow is diverted from the digestive system to the skeletal muscles. Which vascular structure is primarily responsible for this redistribution?

Accepted Answer

Arterioles, by constricting or dilating to regulate flow to specific tissues.

Question 6

Which of the following best describes the function of elastic recoil in arteries?

Accepted Answer

It stores potential energy during ventricular contraction and helps maintain blood flow during diastole without additional ATP expenditure.

Question 7

A doctor measures a patient's blood pressure using a cuff and stethoscope. The first sound heard as the cuff is released corresponds to which value?

Accepted Answer

Systolic pressure, when blood just begins to flow through the artery.

Question 8

Which formula is used to estimate mean arterial pressure (MAP) from systolic ($$P_{sys}) $$and diastolic ($$P_{dia}) $$pressures?

Accepted Answer

$$MAP = P_{dia} + \frac{1}{3}(P_{sys} - P_{dia})$$

Question 9

If the flow rate ($$Q) $$through a vessel is 100 mL/s and the cross-sectional area ($$A) is 20 cm$^2$$, what is the velocity ($$v) of $$blood flow?

Accepted Answer

$$v = \frac{Q}{A} = \frac{100}{20} = 5 cm/s$$

Question 10

Which of the following statements about veins is correct?

Accepted Answer

Veins are less elastic than arteries but are more expandable, allowing them to serve as blood reservoirs.

Question 11

A patient has a mean arterial pressure (MAP) of 93 mmHg, a cardiac output (CO) of 5 L/min, and a total peripheral resistance (TPR) of $$18.6$$ mmHg·min/L. Which equation relates these variables?

Accepted Answer

$$MAP = CO 	imes TPR$$

Question 12

Which of the following best describes the main function of capillaries in the cardiovascular system?

Accepted Answer

They allow for the exchange of oxygen, glucose, and waste products between blood and tissues.

Question 13

If a person has a cardiac output of 7 L/min and a total peripheral resistance of 15 mmHg·min/L, what is their mean arterial pressure (MAP)?

Accepted Answer

$$MAP = CO 	imes TPR = 7 	imes 15 = 105$$ mmHg

Question 14

Which of the following scenarios would most likely result in an increased flow velocity in a vein?

Accepted Answer

Decreasing the diameter of the vein through muscular contraction (increasing tone).

Question 15

Why is it advantageous for the body to slow down blood flow in the capillaries?

Accepted Answer

To maximize the exchange of gases, nutrients, and waste products between blood and tissues.

Question 16

Which tissue type is found in both arteries and veins, contributing to their structural integrity?

Accepted Answer

Fibrous tissue

Question 17

Which of the following best describes the difference between flow rate and flow velocity in the cardiovascular system?

Accepted Answer

Flow rate is the volume of blood passing a point per unit time, while flow velocity is the distance blood travels per unit time.

Question 18

Which of the following is a direct consequence of increased resistance in the peripheral arteries?

Accepted Answer

An increase in mean arterial pressure, assuming cardiac output remains constant.

Question 19

Which property of arteries allows them to act as a pressure reservoir during the cardiac cycle?

Accepted Answer

Elasticity

Question 20

A person has a systolic pressure of 130 mmHg and a diastolic pressure of 85 mmHg. What is their pulse pressure?

Accepted Answer

$$Pulse\ Pressure = Systolic\ Pressure - Diastolic\ Pressure = 130 - 85 = 45$$ mmHg

Cardiovascular System: Blood Vessels, Blood Flow, and Hemodynamics

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