Select the correct events that occur during inspiration. (a) Contraction of diaphragm (b) Contraction of external inter-costal muscles (c) Pulmonary volume decreases (d) Intra pulmonary pressure increases (1) (c) and (d) (2) (a), (b) and (d) (3) only (d) (4) (a) and (b)

Vinay

3 years ago

Correct option:(4)(a) and (b)

Solution:

During inspiration:

Contraction of diaphragm takes place and it moves down.
Downward movement of the diaphragm causes less intrapulmonary pressure than the atmosphere.
External intercostal muscles also contract and cause the ribcage to be able to move outward.
This increases the pulmonary space and decreases the pulmonary pressure.
Both these movements cause inspiration.