I
Circulatory fluid (see circulation ) in multicellular animals.
In many species it also carries hormone s and disease-fighting substances. Blood picks up oxygen from the lungs and nutrients from the gastrointestinal tract and carries them to cells throughout the body for metabolism . It picks up carbon dioxide and other wastes from those cells and transports them to the lungs and excretory organs. Blood composition varies among species. Mammalian blood consists of plasma , red and white cells ( erythrocyte s and leukocyte s), and platelet s (thrombocytes). Blood disorders include polycythemia (abnormal increase in the number of circulating red blood cells), anemia , leukemia , and hemophilia . See also ABO blood-group system ; blood analysis ; blood bank ; blood pressure ; blood transfusion ; blood typing ; Rh blood-group system .
II
[c mediumvioletred] (as used in expressions)
red blood cell
high blood pressure
low blood pressure
white blood cell
blood poisoning
ABO blood group system
blood analysis
blood bank
blood pressure
blood transfusion
blood typing
{{link=Rh blood group system">Rh blood group system