Complete obstruction of a major bronchus usually results in

A. True This ‘atelectasis’ is due to absorption of trapped air.

B. False Local collapse of the lung lowers local intrapleural pressure.

C. False Since the affected lung is collapsed it does not count as dead space.

D. False Local hypoxia in the unventilated segment causes local vasoconstriction.

E. False Vasoconstriction in the collapsed segment prevents deoxygenated blood passing through to the systemic circulation.