Question

Just before an inspiration begins, the pressure within the intrapleural cavity

a. is referred to as the interpleural pressure
b. is less than the pressure within the alveoli
c. is influenced by the tendency of the chest wall to collapse
d. is responsible for causing lung collapse

Answer 1

Intrapleural pressure is the pressure of the air within the pleural cavity. It is always lower than intra-alveolar pressure and atmospheric pressure. This negative pressure prevents lung collapse.

Step-by-step explanation:

Intrapleural pressure refers to the pressure of the air within the pleural cavity. It is always lower than the intra-alveolar pressure and atmospheric pressure.

This negative intrapleural pressure is created by the elastic tissue of the lungs pulling inward and surface tension within the pleural cavity pulling the lungs outward. The intrapleural pressure of approximately -4 mm Hg helps to prevent lung collapse.