Doctors who specialize in hematology (hematologists) are leading the many advances being made in the treatment and prevention of blood diseases. Many people have undergone blood tests or donated blood, but hematology - the study of blood - encompasses much more than this. The Components of Blood and Their Importance An average-sized man has about 12 pints of blood in his body, and an average-sized woman has about nine pints. About 7 to 8 percent of your total body weight is blood. The blood that runs through the veins, arteries, and capillaries is known as whole blood, a mixture of about 55 percent plasma and 45 percent blood cells. bringing waste products to the kidneys and liver, which filter and clean the blood.carrying cells and antibodies that fight infection.
forming blood clots to prevent excess blood loss.transporting oxygen and nutrients to the lungs and tissues.Blood has many different functions, including: It has four main components: plasma, red blood cells, white blood cells, and platelets.
