Blood functions with transporting substances, regulating blood levels of particular substances, or protecting the body.Transport functions of blood includes delivering oxegyn from the lungs and nutriuents, transporting metabolic waste products from cells, and transporting hormones from the endocrine organs to their target organs. Regulating functions of blood include maintaining appropriate body temperature, maintaining normal pH in body tissues, and maintaining adequate fluid volume in the circulatory system. Protective functions of the blood include preventing blood loss and infection.