Question

multiple choice question
the external oblique is a muscle of forced _.
expiration
inspiration

Explanation:

The external oblique is a muscle involved in forced expiration. During forced expiration, the abdominal muscles (including the external oblique) contract to push the diaphragm upwards, reducing the volume of the thoracic cavity and expelling air forcefully. Muscles of inspiration (like the diaphragm and external intercostals) are mainly responsible for increasing the thoracic cavity volume to draw air in.

Answer:

expiration