(Encyclopedia) blood, fluid pumped by the heart that circulates throughout the body via the arteries, veins, and capillaries (see circulatory system ; heart ). An adult male… (Encyclopedia) blood type: see blood groups . (Encyclopedia) blood count, method for determining the number of red (erythrocytes) and white (leukocytes) blood cells in a certain volume of blood. This test can be used as a… (Encyclopedia) blood substitute, substance that mimics the function of blood. Blood substitutes typically concentrate only on reproducing the function of hemoglobin , the molecule… (Encyclopedia) blood bank, site or mobile unit for collecting, processing, typing, and storing whole blood , blood plasma and other blood constituents. Most hospitals maintain… (Encyclopedia) blood groups, differentiation of blood by type, classified according to immunological (antigenic) properties, which are determined by specific substances on the surface… (Encyclopedia) blood transfusion, transfer of blood from one person to another, or from one animal to another of the same species. Transfusions are performed to replace a substantial… (Encyclopedia) blood clotting, process by which the blood coagulates to form solid masses, or clots. In minor injuries, small oval bodies called platelets, or thrombocytes, tend to… (Encyclopedia) Blood Blackfoot: see Blackfoot . (Encyclopedia) blood feud: see vendetta .