Which formula correctly calculates the oxygen content in the blood?

The correct formula for calculating the oxygen content in the blood accounts for both hemoglobin concentration and oxygen saturation, as well as the dissolved oxygen in plasma. The first option accurately incorporates these crucial factors using the recognized components of oxygen transport in blood.

The equation takes into account the percentage of hemoglobin that is saturated with oxygen and the amount of hemoglobin in grams per deciliter (g/dL). Specifically, it uses the coefficient 1.39 mL/g, which represents the amount of oxygen that can be carried by one gram of hemoglobin. This relationship is fundamental in understanding how much oxygen can be transported by the hemoglobin in the blood.

Additionally, the formula includes the term (0.0031 × PO2), which represents the amount of oxygen dissolved in plasma, as oxygen does not solely rely on hemoglobin for transport and exists in a dissolved form in the blood. Here, PO2 refers to the partial pressure of oxygen, and the coefficient 0.0031 mL/g is an established value used to derive the volume of oxygen carried in the dissolved state.

Other options do not adequately reflect the complete picture of oxygen transport. For instance, the second option lacks essential terms and does not conform to standard units necessary for calculating