Question

Name the body structure concerned with the given functional activity:

(c) Helps to increase the volume of the chest activity lengthwise.

Answer 1

Diaphragm is a large, dome-shaped muscle that contracts and flattens which increases the volume of chest in lengthwise.
Contraction creates a vacuum, which pulls air into the lungs i.e. inhalation.
During exhalation, the diaphragm relaxes and returns to its dome-like shape forcing the air out of the lungs.