Expiration during quiet breathing

A) is an active process.
B) requires more muscle contractions than inspiration.
C) is due to contraction of the diaphragm and elevation of the ribs.
D) occurs when the diaphragm and external intercostal muscles relax.
E) is not affected by the elastic properties of the lungs.

Expiration

The process of releasing breath or air from the lungs through the respiratory system.

Diaphragm

A large, dome-shaped muscle located at the base of the lungs and thoracic cavity that contracts and relaxes to aid in the breathing process by creating a vacuum that pulls air into the lungs.

Elastic Properties

Characteristics of materials that allow them to stretch and return to their original shape without permanent deformation.