Question

How does lung volume control inspiration?
Select one:
a. A decrease in lung volume stops the intake of air from the nose and mouth.
b. An increase in lung volume starts the intake of air from the nose and mouth.
c. An increase in lung volume decreases the pressure within the lungs so air can flow inside.

Answer 1

 A decrease in lung volume decreases the pressure within the lungs so air can flow inside. 

Answer 2

Answer:

The correct answer would be c. An increase in lung volume decreases the pressure within the lungs so air can flow inside.

During inspiration or breathing in, the diaphragm contract and move downwards which increases the volume of the chest cavity. Consequently, the volume of the lungs also increases.

In addition, the contraction of intercostal muscles pulls the ribcage outwards and upwards which also increases the size of the chest cavity.

This also increases the lung volume due to which the air pressure inside the lungs is decreased as compared to the air pressure outside the body.

It results in the movement of air inside the lungs from outside the body as air moves from the region of high pressure to the region of low pressure.