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Anatomy & Physiology II Week II: Assignment II Compare blood types and the basis for ABO and Rh incompatibilities. The ABO blood types are the most well known and medically important ones. The ABO blood type can be found in not just in humans, but other primates as well. The four principal types are; A, B, AB, O. An individual’s blood type is determined by a combination of two antibodies and two antigens; namely antigen A, antigen B, Anti A, and Anti B. The surface antigens A, B, and Rh are the most important.
Blood type A has only antigen A, but cannot produce Anti-A antibodies because this will cause a self destruction of their blood. However, B type blood can be injected into their systems. Type B has antigen B, Type AB has both A ; B antigens, but do not make ABO antibodies. Because their blood doesn’t discriminate against any other ABO blood types they are universal receivers for transfusions. Type O has neither antigen A or B. Only O type blood can be shared with any ABO blood type because O type blood does not produce surface antigens. However, person with O type blood can only be injected with O type blood.
Blood can be Rh+ (positive) or Rh- (negative), and should not be mixed. An Rh incompatibility often occurs in pregnancies where the mother blood is Rh- and the fetus is Rh+. This causes destruction of red blood cells. An exposure of both bloods can also occur accidentally through transfusion. Martini, F. H. , and Nath, J. L. (2009). Fundamentals of Anatomy & Physiology. (8th Edition). San Francisco, California: Benjamin Cummings Publishing Company. http://anthro. palomar. edu/blood/ABO_system. htm Identify the process of hemostasis and the cascading events that lead to clot formation.
Hemostasis is the process of changing the blood from its fluid state to a solid state through clot formation by arresting the loss of blood from damaged vessels. The hemostasis process occurs in three stages. Namely; vascular, platelet, and coagulation phase. The vascular phase occurs because of the disruption of the endothelial. This phase is fast and last only 30 minutes, a vascular spasm occur when the vessel contracts. This decreases the diameter of the vessel at the injury site. This constriction causes a slow in the loss of blood or completely stops the loss of blood.
There are three important functions of the platelets. 1. They stick to injured blood vessels. This process is known as platelet adherence. 2. Platelet aggregation, the attaching of one platelet to another to enlarge the forming plug. 3. Providing support for the coagulation cascade process. The coagulation start 30 second or several minutes after damage has been done to the vessel. Blood clotting occurs in this stage when passing blood and additional platelets are trapped in the fibrous tangle. This closes off the damaged portions of the vessel.