North Sea: North Sea, shallow, northeastern arm of the Atlantic Ocean, located between the British Isles and the mainland of northwestern Europe and covering an area of 220,000 square miles (570,000 square km).
Your immune system ignores the surface antigens on your own RBCs. However, your plasma contains antibodies, sometimes called agglutinins , that will attack the antigens on foreign RBCs. When these antibodies attack, the foreign cells agglutinate , or clump together; the process is called agglutination . The plasma of a Type A, Type B, or Type O individual always contains either antiâ A or antiâB antibodies, or both, even if the person has never been exposed to RBCs that carry foreign surface antigens. If you have Type A blood, your plasma contains antiâB antibodies, which will attack Type B surface antigens.
One way the immune system attacks foreign substances in the body is by making large numbers of antibodies. An antibody is a protein that sticks to a specific protein called an antigen. Antibodies circulate throughout the body until they find and attach to the antigen.