The functional unit of the respiratory system is the:
A) alveoli.
B) tertiary bronchi.
C) diaphragm.
D) visceral pleura.

Question

Quizplus · Accepted Answer

The alveoli are the functional unit of the respiratory system because they are the site of gas exchange between the lungs and the bloodstream. Oxygen from the air diffuses across the walls of the alveoli and into the bloodstream, while carbon dioxide from the bloodstream diffuses across the walls of the alveoli and into the air.

The Functional Unit of the Respiratory System Is The