Chapter 20, Problem 1DYKB

_____ 1. Which of the following is not a characteristic of a capillary?

1. a. Fenestrated capillaries have pores that allow for relatively large materials to slip out of the capillary.
2. b. Sinusoid capillaries are the main type of capillary around the brain.
3. c. Capillaries often are arranged in a capillary bed that is supplied by an arteriole.
4. d. The capillary wall consists of an endothelium and basement membrane only—there is no subendothelial layer.

Summary Introduction

Introduction:

Capillary is very small and narrow tubules whose wall is made up of only endothelium, which consist a single layer of epithelial cells. This helps in the easy movement of fluid through them. The movement of the interstitial fluid from the blood to the tissues is due to the high blood pressure at the arterial end. The high osmotic pressures at the venous end of the capillaries enable the movement of fluid into the blood.

Answer to Problem 1DYKB

Correct answer:

Sinusoid capillaries are the main type of capillary around the brain is not a characteristic of capillary.

Therefore, option (b) is correct.

Explanation of Solution

Reasons for the correct statements:

Option (b) is given as “Sinusoid capillaries are the main type of capillary around the brain”. Sinusoid capillaries does not found near the brain. The sinusoid capillaries found in the red bone marrow, liver, spleen and some endocrine gland. Hence, sinusoid capillary found near the brain is not a correct characteristic of a capillary.

Hence, option (b)  is correct.

Reasons for the incorrect statements:

Option (a), is given as “Fenestrated capillaries have pores that allow for relatively large materials to slip out of the capillary”.

Fenestrated capillaries are permeable and are used to filter, release and absorbed large material or proteins. Hence, is incorrect.

Option (c), is given as “Capillaries often are arranged in a capillary bed that is supplied by an arteriole”.

Capillaries form a capillary bed which is a network of capillaries between an artery and a vein and is present in every region of the body. Hence, it  is incorrect.

Option (d), is given as “The capillaries wall consists of an endothelium and basement membrane only-there is no subendothelial layer”.

Capillary is very small and narrow tubules whose wall are made up of only endothelium and basement membrane, which consist a single layer of epithelial cells. Hence, it is incorrect.

Hence, options (a), (c), and (d) are incorrect.

Conclusion

Sinusoid capillaries are found in the red bone marrow, liver, spleen, and some endocrine gland, but they do not found near the brain.