Gas Exchange Takes Place Through the Walls of the _______

Question

Gas exchange takes place through the walls of the _______.
A) alveoli
B) bronchioles
C) larynx
D) trachea

Accepted Answer

Gas exchange occurs in the tiny air sacs called alveoli where oxygen from the inhaled air diffuses into the bloodstream and carbon dioxide from the bloodstream diffuses out into the alveoli to be exhaled. The bronchioles, larynx and trachea are part of the respiratory tract that helps in the passage of air to and from the lungs but gas exchange does not occur through their walls.