If the alveolar PO₂ is 100 mmHg, what will be the PO₂ of blood leaving the pulmonary capillaries in a normal person
A)20 mmHg
B)46 mmHg
C)100 mmHg
D)760 mmHg

Question

Quizplus · Accepted Answer

The PO₂ will remain 100 mmHg as gases diffuse from an area of higher concentration (alveolar air) to an area of lower concentration (blood in capillaries), and in a normal person, the diffusion of oxygen is efficient enough to saturate hemoglobin in red blood cells at this partial pressure. Therefore, there is no significant change in PO₂ between the alveoli and the pulmonary capillaries, and the PO₂ of blood leaving the capillaries will also be 100 mmHg. Choices A, B and D are incorrect because they do not reflect the principles of gas diffusion and the normal physiology of oxygen transport in the lungs.

If the Alveolar PO₂ Is 100 MmHg, What Will Be