Latin: harena, "sand" or "arena" in English, became the general term for "shows" and now it refers more to "sports", etc. unit.

The familiar red vital fluid in the body that contains white and red cells, platelets, proteins, and other elements: Blood is transported throughout the body by the circulatory system.

Blood functions in two directions: arterial and venous. Arterial blood is the means by which oxygen and nutrients are transported to body tissues while venous blood is the means by which carbon dioxide and metabolic by-products are transported to the lungs and kidneys respectively for removal from the body.

A method of using the presence of proteins "A", "B", or both at the surface of red blood cells to characterize an individual's blood type, while "O" signifies the absence of both of the proteins: The ABO blood typing classifies blood into four groups or types; A, B, AB, and O, and each one has.a special antigen and antibody blend or mixture.

a method doctors once used for treating medical disorders in which blood in drawn from a patient's body.

It was believed this would correct imbalances in the blood that caused disease.