Question

What makes alveoli suitable as a gas exchange surface?

A. large total surface area √ , well-supplied with blood vessels √

B. large total surface area √ , well-supplied with blood vessels X

C. large total surface area X , well-supplied with blood vessels √

D. large total surface area X , well-supplied with blood vessels X

Answer 1

The layer of moisture in the alveoli allows gases to dissolve so that they can diffuse quickly. The alveoli have a very large total surface area and a very good blood supply, provided by the dense network of capillaries that surround them.

Answer 2

The large surface area and well-supplied blood vessel make alveoli suitable as a gaseous exchange surface. (OPTION A)

EXPLANATION -

ALVEOLI -

• The smallest functional and structural unit of the lungs facilitates the process of respiration.
• The tiny sac-like structure counts up to 450 million in the lungs.
• The small structure provides them with the large surface area of 100 square meters required for the gaseous exchange.
• An alveolus can fill up to 5-8 liters of gas per minute that helps in the effective working of the human body.
• The gaseous exchange takes place through the membrane of the alveoli therefore they are supplied with a vast intensive network of blood vessels.