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
Blood in stool picture, or with the form of bleeding that is found in another section of the tract. The term "blood in stool" is usually only used to describe visible blood, and not fecal occult blood, which is found only after physical examination and chemical laboratory testing. In infants, the Apt test can be used to distinguish fetal hemoglobin from maternal blood based on the differences in composition of fetal hemoglobin as compared to the hemoglobin found in adults. Blood in the stool can come from many sources. The causes range from not harmful to very serious conditions. A common way to