Pathology. Pathology is the precise study and diagnosis of disease. The word pathology is from Ancient Greek ÏÎ¬Î¸Î¿Ï, pathos which may be translated into English as either experience or suffering. and -Î»Î¿Î³Î¯Î±, -logia, An account of or the study of.
Red cells contain a special protein called hemoglobin, which helps carry oxygen from the lungs to the rest of the body and then returns carbon dioxide from the body to the lungs so it can be exhaled. Blood appears red because of the large number of red blood cells, which get their color from the hemoglobin.
It also helps transport a small portion of carbon dioxide, a product of cell metabolism, from tissues and organs to the lungs, where it is exhaled. The hemoglobin test measures the amount of hemoglobin in a person's sample of blood. A hemoglobin level can be performed alone or with a hematocrit, a test that measures the proportion of blood that is made up of RBCs, to quickly evaluate an individual's red blood cells.