Which of the following is a passive process during which the lungs recoil as the respiratory muscles relax and the thorax decreases in size?

Question

Quizplus · Accepted Answer

Exhalation is a passive process during which the lungs recoil as the respiratory muscles relax and the thorax decreases in size.
Inhalation requires the contraction of the diaphragm to enlarge the thoracic cavity and draw air into the lungs. 
External respiration refers to the exchange of gases between the atmosphere and the blood through the alveoli. 
Internal respiration refers to the exchange of gases between the blood and the body cells.

Which of the Following Is a Passive Process During Which