Chapter 12 BLOOD Explain Activity Basics of Blood Transfusions Blood transfusion is the transferring of blood from one person, a donor, to another person, the recipient. Blood transfusions can be life saving in some cases, like if someone looses a lot of blood because of an injury like a gunshot. People may also need a blood transfusion if they have some sort of disease like sickle cell disease, anemia, or hemophilia Blood transfusions can also, in rare occasions, transmit disease to the people that get them. One disease that can be transmitted is AIDS. Blood transfusions are also used to replace blood that might be lost from someone having surgery. Early scientists didn’t know that blood had different types so they would put the wrong type into someone that needed a blood transfusion and that person would be in terrible pain, damaged organs, and in some cases the person would die. Agglutination is the clumping of red blood cells after a transfusion. Due to a reaction between molecules on the red blood cell surface called antigens, and proteins called antibodies. When a donor gives blood they take the plasma, and put it back into your system. They do not need the plasma they just use mainly the red blood cells. Plasma is about 55% of your blood. When blood is separated to put the plasma back in, there is a “buffy coat” between the plasma and the red blood cells, which is made up of white blood cells and plasma. This is a very small portion of the blood and is kept along with the red blood cells. Different blood groups The four types of blood are A, B, AB, and O. o Each Type can be RH – or RH + which tells you if that type of blood contains antigen D or not. RH + blood can receive RH + or RH – but RH – blood can only receive RH – blood. A blood has only A antigens in it. B Blood only has B antigens in it. AB blood has both, and O has neither. Blood can take any type of Antigen that it already has in it but cannot take any other antigen. Eruthroblastosis Fetalis If an RH- woman is pregnant with an RH+ fetus, when the fetus is born when the placental membranes tear, some of the RH+ blood from the fetus enters the maternal circulation which causes the maternal tissues to begin producing anti-RH antibodies. If that woman then has another baby that is RH+, those antibodies that were produced will attack the fetus and destroys the fetal red blood cells.