In Mammals, Most Gas Exchange Between the Atmosphere and the Pulmonary

Question

In mammals, most gas exchange between the atmosphere and the pulmonary blood occurs in the
A) trachea.
B) larynx.
C) bronchi.
D) bronchioles.
E) alveoli.

Accepted Answer

Alveoli are small air sacs in the lungs where gas exchange occurs. Oxygen from the air diffuses across the thin walls of the alveoli and into the bloodstream while carbon dioxide diffuses out of the bloodstream and into the alveoli to be exhaled.