Question 1

Which of the following best explains why elastic (conducting) arteries, such as the aorta, are located close to the heart?

Accepted Answer

Their ability to expand and recoil helps dampen the pressure fluctuations from ventricular contractions, ensuring continuous blood flow.

Question 2

Which vessel type is primarily responsible for regulating resistance and blood flow to capillary beds?

Accepted Answer

Arterioles

Question 3

What is the main function of capillaries in the circulatory system?

Accepted Answer

To act as exchange vessels for nutrients, gases, and waste products

Question 4

Which structural feature is unique to veins and helps prevent the backflow of blood, especially in the limbs?

Accepted Answer

Valves

Question 5

According to the relationship between cross-sectional area and blood velocity, where is blood flow velocity the slowest?

Accepted Answer

Capillaries

Question 6

Which of the following best describes the effect of vasoconstriction on blood pressure?

Accepted Answer

Vasoconstriction decreases the diameter of arterioles, increasing blood pressure.

Question 7

Which sequence correctly describes the smooth muscle relaxation pathway leading to vasodilation?

Accepted Answer

Acetylcholine → IP3 production → Ca$$^{2+}$$ release → NO synthase activation → NO production → cGMP synthesis → Smooth muscle relaxation

Question 8

A patient is given a drug that inhibits phosphodiesterase in vascular smooth muscle. What is the expected physiological effect?

Accepted Answer

Increased cGMP levels, leading to prolonged smooth muscle relaxation and increased blood flow

Question 9

Why do giraffes require a much higher systolic blood pressure than humans?

Accepted Answer

To pump blood up their long necks against gravity to reach the brain

Question 10

During blood pressure measurement with a sphygmomanometer, what does the pressure at which the first Korotkoff sounds are heard represent?

Accepted Answer

Systolic pressure

Question 11

Which of the following best explains why blood velocity increases again as blood moves from capillaries to veins?

Accepted Answer

The total cross-sectional area of veins is less than that of capillaries, causing blood to converge and velocity to increase.

Question 12

Which mechanism is primarily responsible for returning excess interstitial fluid to the circulatory system?

Accepted Answer

Lymphatic vessels

Question 13

What is the main force driving fluid out of capillaries at the arterial end?

Accepted Answer

Blood pressure (hydrostatic pressure)

Question 14

Which of the following best describes the role of plasma proteins in capillary exchange?

Accepted Answer

They create an osmotic pressure that draws water back into the capillaries from the interstitial fluid.

Question 15

A person stands still for long periods of time and develops swelling in their lower legs. Which physiological mechanism is most likely impaired?

Accepted Answer

The muscular pump that assists venous return

Question 16

Which of the following equations correctly represents the relationship between blood flow ($$Q$$), pressure difference ($$\Delta P$$), and resistance ($$R) in a $$vessel?

Accepted Answer

$$Q = \Delta P / R$$

Question 17

If the osmotic pressure in the capillaries decreases due to a loss of plasma proteins, what is the most likely consequence?

Accepted Answer

Increased net movement of fluid into the interstitial space, leading to edema

Question 18

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

Accepted Answer

They regulate blood flow into capillary beds based on local chemical conditions.

Question 19

Which of the following is a correct statement about the structure of capillaries?

Accepted Answer

They consist mainly of a single layer of endothelial cells and a basal lamina.

Question 20

Which of the following best explains why veins can accommodate a larger volume of blood compared to arteries?

Accepted Answer

Veins have larger lumens and thinner walls, allowing them to serve as blood reservoirs.

BIO 102 Chapter 42 Part 1 B

Guida di studio - Domande di pratica

Study guide - Flashcard