Gas Exchange in the Lungs Occurs Across the Respiratory Membrane

Question

Gas exchange in the lungs occurs across the respiratory membrane by the process of
A)osmosis
B)diffusion
C)exocytosis
D)active transport
E)filtration

Accepted Answer

Gas exchange in the lungs occurs through the process of diffusion, where oxygen from the air in the lungs diffuses through the walls of the alveoli and into the bloodstream, while carbon dioxide from the bloodstream diffuses out of the capillaries and into the alveoli to be exhaled. Osmosis, exocytosis, active transport, and filtration are not involved in gas exchange in the lungs.