Question 1

Which of the following best explains how capillary walls facilitate the exchange of nutrients and gases between blood and tissues?

Accepted Answer

Capillary walls are made of a single layer of endothelial cells, allowing for efficient diffusion of small molecules.

Question 2

Which mechanism is primarily responsible for the movement of small, water-soluble substances out of the capillaries?

Accepted Answer

Simple diffusion through intercellular clefts

Question 3

Which two mechanisms are most important for substance exchange across capillary walls?

Accepted Answer

Diffusion and vesicular transport (transcytosis)

Question 4

What creates hydrostatic pressure in blood vessels, and what is the main source of colloid osmotic pressure in capillaries?

Accepted Answer

Hydrostatic pressure is generated by the pumping action of the heart; colloid osmotic pressure is mainly due to plasma proteins such as albumin.

Question 5

During filtration at the arterial end of a capillary, which direction does fluid move, and what is the main force responsible for this movement?

Accepted Answer

Fluid moves out of the capillary due to hydrostatic pressure.

Question 6

Which way does fluid move during absorption at the venous end of a capillary, and what is the main force responsible?

Accepted Answer

Fluid moves into the capillary due to colloid osmotic pressure.

Question 7

A patient with liver disease has low plasma protein levels. Using the Starling equation $$ J_v = K_f \left[ (P_c - P_i) - \sigma (\pi_c - \pi_i) \right] $$, predict the effect on fluid movement across capillaries.

Accepted Answer

Decreased plasma proteins lower $$ \pi_c $$, increasing net filtration and leading to edema.

Question 8

Which condition can arise if excess interstitial fluid cannot be removed by the lymphatic system?

Accepted Answer

Edema

Question 9

How is interstitial fluid different from plasma, and how is it different from lymph?

Accepted Answer

Interstitial fluid has fewer proteins than plasma and is similar to lymph except lymph contains more immune cells.

Question 10

What do lymphatic vessels and veins have in common?

Accepted Answer

Both contain valves to prevent backflow of fluid.

Question 11

Where do lymphatic vessels originate, and what is their primary function?

Accepted Answer

They originate from interstitial spaces and return excess fluid and proteins to the bloodstream.

Question 12

Which of the following is a common cause of edema?

Accepted Answer

Congestive heart failure

Question 13

A patient with kidney disease has proteinuria (loss of protein in urine). How does this affect capillary exchange?

Accepted Answer

It decreases plasma colloid osmotic pressure, increasing filtration and causing edema.

Question 14

Which equation best describes the net movement of fluid across capillary walls?

Accepted Answer

$$ J_v = K_f \left[ (P_c - P_i) - \sigma (\pi_c - \pi_i) \right] $$

Question 15

Which of the following is NOT a function of the lymphatic system?

Accepted Answer

Producing red blood cells in adults

Question 16

During pregnancy, why is edema more likely to occur?

Accepted Answer

Venous pressure increases due to the enlarged uterus, raising capillary hydrostatic pressure.

Question 17

Which of the following best describes the role of colloid osmotic pressure in capillary exchange?

Accepted Answer

It draws fluid back into capillaries from the interstitial space.

Question 18

A patient with congestive heart failure develops peripheral edema. Which change in Starling forces is most likely responsible?

Accepted Answer

Increased capillary hydrostatic pressure ($$ P_c )$$

Question 19

Which of the following is a unique function of the lymphatic system compared to the circulatory system?

Accepted Answer

Absorbing and transporting dietary fats from the intestine

Question 20

Which scenario would most likely result in decreased absorption of fluid into capillaries?

Accepted Answer

Decreased plasma protein concentration

Capillary Exchange and the Lymphatic System: Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard