Question

practice 11
what happens to the diaphragm and intercostal muscles during exhalation?
they relax
they spasm
they twitch
they expand
they contract

Explanation:

During exhalation, the diaphragm and intercostal muscles relax. When they relax, the volume of the thoracic cavity decreases. This increase in pressure (compared to the outside air) forces air out of the lungs. Spasming, twitching, expanding, or contracting (in the context of inhalation, muscles contract) are not the correct actions during exhalation for these muscles.

Answer:

They relax