Question

Name the body structure concerned with the given functional activity:

Increases the volume of the chest cavity in a lengthwise direction.

Answer 1

• The diaphragm, located below the lungs, is the major muscle of respiration. It is a large, dome-shaped muscle that contracts rhythmically and continually, and most of the time, involuntarily.
• Upon inhalation, the diaphragm contracts and flattens and the chest cavity enlarges.
• During exhalation, the diaphragm relaxes and returns to its dome-like shape forcing the air out of the lungs.
• Thus the diaphragm contracts to increase the thoracic cavity lengthwise.