Some partial pressures for oxygen (in mmHg) in different parts of the respira- tory system are given below. Given that atmospheric air has O 2 at 160 mmHg, which ones are reasonable values? A. Capillary blood entering the alveoli has 40 mmHg, the alveolar air has 160 mmHg, capillary blood leaving the alveoli has 100 mmHg. B. Capillary blood entering the alveoli has 40 mmHg, the alveolar air has 104 mmHg, capillary blood leaving the alveoli has 100 mmHg. C. Capillary blood entering the alveoli has 40 mmHg, the alveolar air has 104 mmHg, capillary blood leaving the alveoli has 40 mmHg. D. Capillary blood entering the alveoli has 104 mmHg, the alveolar air has 100 mmHg, capillary blood leaving the alveoli has 40 mmHg.
Option B. Capillary blood entering the alveoli has 40 mmHg, the alveolar air has 104 mmHg, capillary blood leaving the alveoli has 100 mmHg.