Question

During inspiration 

A. Intrapleural pressure is lowest at mid-inspiration. 

B. Intrapulmonary pressure is lowest around mid-inspiration. 

C. Intraoesophageal pressure is lowest at mid-inspiration. 

D. The rate of air flow is greatest at end-inspiration. 

E. The lung volume/intrapleural pressure relationship is the same as in expiration.

Answer 1

A. False It is lowest at the end of inspiration. 

B. True After mid-inspiration, intrapulmonary pressure rises as air is drawn into the lungs. 

C. False Its pattern is similar to that of intrapleural pressure. 

D. False It is greatest at mid-inspiration; it depends on the mouth:alveoli pressure gradient. 

E. False Volume changes lag behind pressure changes to give a hysteresis loop.