Air sacs in birds
A) function as lungs.
B) provide additional gas exchange surfaces.
C) are the primary sites of gas exchange.
D) facilitate efficient air movement in the lungs.
E) direct countercurrent air flow into the lungs.

Question

Quizplus · Accepted Answer

Air sacs in birds facilitate efficient air movement in the lungs by allowing a unidirectional flow of air, which helps maintain a constant supply of fresh air to the lungs during both inhalation and exhalation.

Air Sacs in Birds