Question

Lungs have a large number of alveoli for

• A. More nerve supply
• B. More surface area for diffusion of gases
• C. Having spongy texture and proper shape
• D. More space for increasing volume of inspired air

Answer 1

The correct option is B

More surface area for diffusion of gases

The correct option is B.

Explanation of the correct option:

1. Alveoli are balloon-like structures that occupy most of the space present in the lungs.
2. Alveoli are the place where the exchange of gases takes place.
3. Carbon dioxide and oxygen are exchanged at the tissue and alveolar levels.
4. Alveoli serve primarily to increase the surface area available for gas exchange.
5. Each of the lungs contains roughly 300 million alveoli.
6. These tiny air sacs offer the best location for gas diffusion into and out of the blood (gas exchange).
7. The surface area of the alveoli is enormous.

Explanation of the incorrect options:

Option A:

1. The lungs' pulmonary plexus, which combines sympathetic and parasympathetic innervations with the phrenic nerve, are the two main sources of innervations for the lung.
2. The pulmonary plexus is made up of efferent and afferent autonomic nerve fibers at the base of the lung.

Option C:

1. The walls of each alveolus are extremely thin and cup-shaped.
2. As alveolar cells and elastic connective tissue surround primarily air gaps, the lungs are soft and pliable.

Option D:

1. It's not just the diaphragm that offers our lungs the space they require.
2. To give the lungs more room, our rib muscles also pull the ribs upward and outward.
3. We breathe in through our mouth and nose at the same moment, and the air travels down our trachea or windpipe.

Final answer: Lungs have a large number of alveoli for more surface area for diffusion of gases.