Refer to the figure showing the respiratory system in birds. Based on the figure, which statement about the air sacs of birds is true?

Question

Refer to the figure showing the respiratory system in birds.  Based on the figure, which statement about the air sacs of birds is true?

Quizplus · Accepted Answer

Air flows from the posterior air sacs into the lungs. In birds, the air sacs are connected to the lungs and they act as reservoirs for air, supplying oxygen-rich air to the lungs during both inhalation and exhalation. During inhalation, air flows through the trachea and into the posterior air sacs, then during exhalation, the air sacs contract, and air flows through the lungs and into the anterior air sacs before being expelled through the trachea. Therefore, statement D is true. Statements A, B, C, and E are false based on the diagram.

Refer to the Figure Showing the Respiratory System in Birds