Respiratory cycle

Definition

The respiratory cycle is the process by which an individual inhales oxygen into the lungs and exhales carbon dioxide out of the lungs. It consists of a single inhalation (inspiration) followed by a single exhalation (expiration), completing one cycle.

Related terms

Inhalation:

The act of drawing air into the lungs, primarily involving the diaphragm's downward movement to increase chest cavity volume.

Exhalation:

The act of releasing air from the lungs, involving the upward movement of the diaphragm to decrease chest cavity volume.

Diaphragm:

A major muscle involved in breathing that contracts during inhalation to expand the lungs and relaxes during exhalation to help expel air