Question

The exchange of materials between the blood and the interstitial fluid occurs in the
A. Veins
B. Capillaries
C. Arteries
D. Arterioles

Answer 1

Hint: Blood is red colour red colour substance . That contains formed elements and plasma. Formed elements are red blood cells, white blood cells, and platelets.

Complete answer:
Capillaries are essential for the delivery of oxygen to the tissue and in the exchange of nutrients between blood and interstitial fluid surrounding the cells.
This function is well supported by the anatomy of the vessels.
The thin walls of the capillaries are composed of a single layer of endothelial cells.
As a result gases such as Oxygen and carbon dioxide can diffuse through the walls of capillaries as well as lipid-soluble substances.
Capillaries also play an important role in regulating the relative volume of the blood and interstitial fluid by allowing a bulk flow through their walls. This exchange of the water and solutes occur in response to the pressure gradient across the capillary wall.

So, the correct answer is “Option B”.

Note: During early embryonic development new capillaries are formed through vasculogenesis. Capillary is a small blood vessel from 5 to 10 micrometers in diameter and having a Wall of endothelial cells. Capillaries are the smallest blood vessels in the body that convey blood between the arterioles and venules. These microvessels are the site of exchange of any substance with the interstitial fluid surrounding them.