PATHOLOGY

Detailed explanation-1: -Tiny air sacs at the end of the bronchioles (tiny branches of air tubes in the lungs). The alveoli are where the lungs and the blood exchange oxygen and carbon dioxide during the process of breathing in and breathing out.

Detailed explanation-2: -Each bronchi is divided into smaller branches called as the bronchioles. At the end of each bronchioles are the microscopic sacs called as the alveoli.

Detailed explanation-3: -Air sacs serve as internal compartments which hold air and facilitate internal air passage to allow birds to have a continuous flow of large volumes of air through the lungs as a way to increase oxygen exchange capacity and efficiency.