Question

During inspiration

A. Venous return to the heart is increased.

B. More energy is expended than during expiration.

C. Lung expansion is assisted by surface tension forces in the alveoli.

D. Lung expansion begins when intrapleural pressure falls below atmospheric.

E. Lung expansion ends when intrapulmonary pressure falls to atmospheric.

Answer 1

A. True By decreasing intrathoracic venous pressure.

B. True Expiration is assisted by the elastic recoil of the lungs and thoracic cage.

C. False Surface tension is a force to be overcome in inspiration.

D. False Expansion begins when intrapulmonary pressure falls below atmospheric.

E. True There is no pressure gradient at this point to drive air.