Human Anatomy and Physiology : Help with Capillary Physiology

Study concepts, example questions & explanations for Human Anatomy and Physiology

varsity tutors app store varsity tutors android store

Example Questions

Example Question #1 : Help With Capillary Physiology

Which scenario causes fluid to return to the capillaries from the interstitial fluid?

Possible Answers:

The interstitial hydrostatic pressure becomes greater than the capillary hydrostatic pressure

The interstitial osmotic pressure becomes greater than the arteriole hydrostatic pressure

The interstitial osmotic pressure becomes weaker than the capillary hydrostatic pressure

The interstitial osmotic pressure becomes greater than the capillary hydrostatic pressure

Correct answer:

The interstitial osmotic pressure becomes greater than the capillary hydrostatic pressure

Explanation:

Fluid movement into and out of capillaries is mainly dependent on two forces: hydrostatic pressure and osmotic pressure. Hydrostatic pressure is determined by fluid volume and the pressure of the fluid against the capillary walls. Osmotic pressure is determined by osmotic gradient, pulling water in the direction of higher protein concentration. Osmotic pressure is largely directed into the capillary due to the high concentration of albumin in the plasma. The osmotic pressure outside of the capillary remains relatively constant, however, as the capillary moves from the arteriole end to the venule end the hydrostatic pressure drops significantly. Eventually, the osmotic pressure in the interstitium becomes greater than the hydrostatic pressure in the capillary, and fluid returns to the capillaries.

Example Question #2 : Help With Capillary Physiology

Which of the following types of blood vessels allow for diffusion into the interstitium?

Possible Answers:

Capillaries only

Arterioles only

Arteries, veins and capillaries

Both arterioles and venules

Venules only

Correct answer:

Capillaries only

Explanation:

The walls of arteries, arterioles, veins, and venules are all much too thick to allow for the diffusion of substances. However, capillaries only have simple squamous endothelial cells lining their walls, without muscular and/or elastic tissue surrounding them. Their walls are thin enough to allow for diffusion of substances into the interstitium.

Example Question #2 : Help With Capillary Physiology

What type of cells are found wrapped around the endothelial cells of capillaries? 

Possible Answers:

Pericytes (Rouget cells) 

Schwann cells 

None of these

Monocytes

Purkinje fibers 

Correct answer:

Pericytes (Rouget cells) 

Explanation:

Pericytes, sometimes referred to as Rouget cells, are cells that wrap around the endothelial cells of capillaries. These cells play an important role in angiogenesis, the process of formation of new blood vessels. Monocytes are macrophages of the immune system, Purkinje fibers are found in the heart, and allow conductance of electricity to the cardiomyocytes, Schwann cells are glial cells in the peripheral nervous system that myelinate axons.

Example Question #4 : Help With Capillary Physiology

Which of the following is true in regards to capillaries?

Possible Answers:

They have thick walls

They contain an extensive layer of smooth muscle

They are under high pressure

They have the largest total cross sectional and surface area

Correct answer:

They have the largest total cross sectional and surface area

Explanation:

Capillaries have the largest total cross sectional and surface area. They are thin-walled and consist of a single layer of endothelial cells surrounded by basal lamina. Capillaries are the site of exchange of nutrients, water, and gases.

Arteries are thick-walled, with extensive elastic tissue and smooth muscle. Arteries are under high pressure.

Example Question #3 : Help With Capillary Physiology

Which component of the circulatory system contains the largest percentage of blood volume?

Possible Answers:

Systemic veins

Aorta

Capillary networks

Systemic arteries

Pulmonary arteries

Correct answer:

Systemic veins

Explanation:

At any given moment, the majority of blood in the human body can be found in the venous network. Veins contain 64% of the body's blood, making it the largest reservoir of blood in the body. Capillary networks contain the largest surface area of blood, however, not the largest percentage of blood volume.

Learning Tools by Varsity Tutors

Incompatible Browser

Please upgrade or download one of the following browsers to use Instant Tutoring: