Question

i) What is importance of thin walls of blood capillaries? (a) Thin walls of blood capillaries provide them protection. (b) Exchange of materials between the blood and surrounding cells take place across the thin walls of blood capillaries. (c) Thin walls of blood capillaries help on smooth flow of blood. (d) All of the above.​

Answer 1

Answer:

B is the Answer, Exchange of Materials Between the Blood And surrounding Cells Take place Across the Thin walls of Blood Cappilarries

Answer 2

The correct solution is option b, the thin walls of blood capillaries help in the exchange of materials between blood and the surrounding tissues.

• The heart and blood vessels comprise the circulatory system.
• Capillaries are the smallest of blood vessels, approximately with a diameter of 5 micrometres. A single Redblood cell barely fits in this diameter.
• Capillaries connect the arterial system to the venous system.
• The walls of the capillaries are made up of a thin layer called endothelium which is usually one cell in thickness. The endothelium is surrounded by a basement membrane.
• These thin walls are permeable and help in the optimal exchange of nutrients and oxygen from the blood into the tissues and also transfer the accumulated waste products in the tissues back to the blood.
• The mechanism of Passive diffusion and Pinocytosis(intake of small molecules in a suspended liquid form by cells) thus overall seems to be done efficiently through the thin capillary wall.