An essential fluid in our bodies that carries out the critical functions of transporting oxygen and nutrients to our cells and getting rid of carbon dioxide and other waste products. In addition, it plays a vital role in our immune system and in maintaining a relatively constant body temperature. It is a highly specialized tissue composed of many different kinds of components produced in bone marrow. | blood |
A relatively large type of blood cell that transports oxygen from the lungs to all of the living tissues of the body and carries away carbon dioxide. Normally, 40-45% of human blood volume consists of this type of cell. These cells are produced continuously in our bone marrow from stem cells. | erythrocyte (red cell) |
The gas transporting protein molecule that normally makes up 95% of the volume of red cells in blood. The color of blood is primarily due to these molecules when they are chemically bound to oxygen. | hemoglobin |
A kind of blood cell that exists in variable numbers and types but makes up a very small part of human blood volume. Some of these cells provide a physiological defense against infection. As a result, their numbers increase when the body is under attack by bacteria and viruses. Some other types have the function of getting rid of old unneeded blood cells. | leukocyte (white cell) |
A type of blood cell that coagulates and clots blood when there is an injury to a blood vessel. | thrombocyte (platelet) |
The relatively clear liquid medium in blood which carries the red cells, white cells, and platelets. Most of blood's volume is made up of this liquid. As the heart pumps blood to cells throughout the body, this liquid brings them nourishment and removes the waste products of metabolism. | plasma |
The clumping together of red cells in blood as a result of antibodies attaching to antigens on the surface of the cells. This occurs when blood of different types is mixed together. | agglutination |
A kind of relatively large molecule found on the surface of red blood cells. These molecules provide the specific signature or identity to blood—i.e., the blood type. When alien forms of these molecules are introduced into the body via a transfusion of the wrong type of blood, they stimulate the production or mobilization of other molecules to get rid of the alien blood. | antigen |
A kind of protein produced by the body to identify and neutralize or destroy alien antigens by binding to them. These proteins are involved in the rejection of mismatched blood transfusions and organ transplants. They are also responsible for recognizing and eliminating bacteria and viruses. These proteins provide a major defense for our bodies against invasion by alien organisms. | antibody |
The name of the system of over 100 antigens on the surface of human body tissue cells that can be recognized by some kinds of white blood cells and potentially lead to the rejection of these tissues if they are alien. When organ transplants fail, it is usually due to an incompatibility for this system. | HLA system (human leukocyte antigen system) |