A series of related blood types constitutes a blood group system, such as the Rh or ABO system. The frequencies of the ABO and Rh blood types vary from population to population. Blood Type A- If the red blood cell has only “A” molecules on it. Blood Type B- If the red blood cell has only “B” molecules on it.
The major blood types (A, B, AB, and O) are determined by the protein markers (antigens) present on the surface of red blood cells. Coombs test: A blood test looking for antibodies that could bind to and destroy red blood cells.
The blue arrows represent the flow of deoxygenated blood through the right side of the heart. The red arrows represent the flow of oxygenated blood through the left side of the heart. Diagram: Blue arrows demonstrate flow of deoxygenated blood through the right side of the heart.