ANATOMY

Detailed explanation-1: -Quiet expiration is a passive process occurring at rest, whereas forced expiration is an active process that occurs during exercise. Quiet respiration depends on elastic recoil of the lungs after inspiratory stretching, elastic recoil of the costal cartilages, and the relaxation of the inspiratory muscles.

Detailed explanation-2: -During quiet breathing at rest, expiration is passive, air leaving the lungs principally as a result of the relaxation of the inspiratory striated muscles of breathing and elastic recoil of the lungs.

Detailed explanation-3: -In healthy people quiet expiration or exhalation is passive and relies on elastic recoil of the stretched lungs as the inspiratory muscles relax, rather than on muscle contraction.

Detailed explanation-4: -Whereas, during the expiration diaphragm muscles relax without the use of energy intra-pulmonary pressure becomes higher than the atmospheric pressure and air noshes out. Thus, it is a passive process.

Detailed explanation-5: -While expiration is generally a passive process, it can also be an active and forced process. There are two groups of muscles that are involved in forced exhalation.