Difference in the trajectory between inspiratory and the expiratory loop in the compliance curve is due to:
The difference in the inspiratory and expiratory component exists in compliance curve and it is called hysteresis The difference exists because greater trans pulmonary pressure is required to open a closed airway owing to deficit of the surfactants than to keep an open airway from closing, reflecting abundant surfactant Ref : Guyton and Hall textbook of medical physiology 12th edition, page number:319,320,321
Difference between alveolar pressure during inspiration and expiration
Difference between concentration of the surfactants during inspiration and expiration
Difference in airway resistance during inspiration and expiration
Inspiration is active and expiration is passive
Respiratory system