Blood gas tension Blood gas tension Blood gas tension refers to the partial pressure of gases in blood. There are several significant purposes for measuring gas tension; the most common gas tensions measured are oxygen tension (PO), the carbon dioxide tension (PCO) and carbon monoxide tension (PCO). The subscript "x" in each symbol represents the source of the gas being measured; ""a"" meaning arterial, ""A"" being alveolar, ""v"" being venous, ""c"" being capillary. Blood gas tests (such as arterial blood gas tests) measure these partial pressures. PO – Partial pressure of oxygen at sea level (765 mmHg) in arterial blood is between 75
Hemoglobin variants lengthy list of common hemoglobin variants, there are some variants that are less common. These variants are considered silent, which means that they have no signs or symptoms. They usually affect the functionality and/or the stability of the hemoglobin molecule. With most of these variants are mutations in the alpha globin gene that result in an abnormally long alpha chain and an unstable hemoglobin molecules. Hemoglobin F is the primary hemoglobin produced by the fetus. The hemoglobin transports oxygen efficiently in a low oxygen environment. The hemoglobin production stops at birth and decreases to adult levels by the age of