Question

In the lungs, oxygen diffuses out of the alveoli and into where?

Answer 1

capillaries

In the lungs, oxygen diffuses out of the alveoli and into the capillaries surrounding the alveoli. Oxygen  about 98 percent  binds reversibly to the respiratory pigment hemoglobin found in red blood cells  RBCs . RBCs carry oxygen to the tissues where oxygen dissociates from the hemoglobin and diffuses into the cells of the tissues. More specifically, alveolar P O 2.