Which of the following statements BEST describes the exchange of gas in the alveoli?
A) Blood moves by way of the pulmonary capillaries, air arrives at the alveoli, and osmosis occurs.
B) Blood moves from the left heart to the lungs, air arrives in the alveoli sacks, and diffusion occurs.
C) Air moves into the airway, blood arrives via the pulmonary veins, and osmosis occurs.
D) Air moves into the alveoli, blood is transported by the pulmonary capillaries, and diffusion occurs.

Question

Quizplus · Accepted Answer

Air moves into the alveoli, and blood is transported by the pulmonary capillaries to the alveoli. Oxygen diffuses through the walls of the alveoli into the bloodstream, and carbon dioxide diffuses from the bloodstream into the alveoli to be exhaled. Therefore, option D is the correct statement that describes the exchange of gas in the alveoli.

Which of the Following Statements BEST Describes the Exchange of Gas