In Reference to a Normally Expanded Lung,the

Question

In reference to a normally expanded lung,the
A) intrapulmonic pressure is less than intrapleural pressure.
B) intrapleural pressure is greater than atmospheric pressure.
C) intrapulmonic pressure is greater than intrapleural pressure.
D) intrapleural, intrapulmonic, and atmospheric pressures are equal.

Accepted Answer

In a normally expanded lung, the intrapulmonic pressure is greater than the intrapleural pressure due to the elastic recoil of the lung tissue. The pressure inside the lung becomes negative relative to atmospheric pressure during inspiration and positive during expiration, causing air to flow in and out of the lungs. However, the intrapleural pressure is always negative relative to the intrapulmonic pressure, which helps to maintain the structural integrity of the lung and prevent it from collapsing.