Final answer:
The ratio of oxyhemoglobin to total hemoglobin in human blood is heavily influenced by oxygen saturation levels and the presence of competing gases.
Step-by-step explanation:
The ratio of the concentration of oxyhemoglobin to the concentration of total hemoglobin, which includes Hgb derivatives like carboxyhemoglobin, is predominantly dependent on the oxygen levels in the environment and the presence of competing gases, such as carbon monoxide (CO). In normal physiological conditions, hemoglobin in the blood is 95-96% saturated with oxygen, leading to a high concentration of oxyhemoglobin. Hemoglobin has a quaternary structure capable of binding four oxygen molecules; it forms oxyhemoglobin (HbO2) upon oxygen binding. The total hemoglobin concentration includes not only the oxyhemoglobin but also reduced hemoglobin (HHb) and other forms, including carboxyhemoglobin (HbCO), which forms when hemoglobin binds with CO.
Since CO has a binding affinity to hemoglobin 200 times stronger than that of oxygen, exposure to CO can significantly alter the ratio of oxyhemoglobin to total hemoglobin. In contrast, synthetic oxygen carriers have been designed to mimic the oxygen-carrying capacity of hemoglobin, maintaining dissolved oxygen concentrations comparable to those achieved by natural hemoglobin, thus affecting the ratio in a different context.