Ventilation in birds is accomplished by expansion and contraction of the
A)air sacs.
B)trachea.
C)lungs.
D)diaphragm.
E)air capillaries.

Question

Quizplus · Accepted Answer

Birds have a unique respiratory system, consisting of a one-way flow of air through a system of air sacs and lung tissue. When a bird breathes in, air enters the posterior air sacs, and when it exhales, the air moves through the lungs and into the anterior air sacs. This system allows for a constant flow of oxygen-rich air, and aids in the efficient exchange of gases. Therefore, ventilation in birds is accomplished by the expansion and contraction of the air sacs.

Ventilation in Birds Is Accomplished by Expansion and Contraction of the