Dissolved oxygen content at PaO2 of 100 mmHg is approximately:

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Dissolved oxygen content at PaO2 of 100 mmHg is approximately:

Oxygen dissolved in plasma is very small compared to what Hb carries. According to Henry’s law, the amount of dissolved O2 in blood is about 0.003 ml O2 per dL of blood for each mmHg of PaO2. At a PaO2 of 100 mmHg, dissolved O2 ≈ 0.003 × 100 = 0.3 ml O2 per 100 ml of blood. The rest of the O2 content comes from O2 bound to hemoglobin, which is why arterial blood total O2 content is around 20 ml O2 per 100 ml, with only ~0.3 ml being dissolved. The value 0.3 ml per 100 ml matches this dissolved fraction, whereas the other options misstate the amount or unit.

Oxygen dissolved in plasma is very small compared to what Hb carries. According to Henry’s law, the amount of dissolved O2 in blood is about 0.003 ml O2 per dL of blood for each mmHg of PaO2. At a PaO2 of 100 mmHg, dissolved O2 ≈ 0.003 × 100 = 0.3 ml O2 per 100 ml of blood. The rest of the O2 content comes from O2 bound to hemoglobin, which is why arterial blood total O2 content is around 20 ml O2 per 100 ml, with only ~0.3 ml being dissolved. The value 0.3 ml per 100 ml matches this dissolved fraction, whereas the other options misstate the amount or unit.

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