You're resting on the couch watching TV.Which of the following is the most likely reflection of the values in your body? Regarding the partial pressures of O₂ and CO₂,which of the following statements is true in a normal person at rest?

Question

Quizplus · Accepted Answer

Option C is the only statement that accurately reflects the typical partial pressures of O₂ and CO₂ in a normal person at rest. Atmospheric PO₂ is indeed ~100 mmHg, but alveolar PO₂ is around 100 mmHg as well, not 160 mmHg (option A is incorrect). The PCO₂ in the air is indeed ~40 mmHg, but the alveolar PCO₂ is around 40 mmHg as well, not 60 mmHg (option B is incorrect). Option D and E are both incorrect, as systemic venous PCO₂ is greater than systemic arterial PCO₂ (due to CO₂ produced by the body's cells) and pulmonary arterial PCO₂ is greater than pulmonary venous PCO₂ (since the lungs remove CO₂ from the blood).

You're Resting on the Couch Watching TV