اختبار حالي تخلص فسيو 2 PDF

# تلخيص لاب فسيو ## Erythrocytes - are pliable cells - bend and twist as they pass through the vasculature - Because of this pliability, and because they lack a nucleus, red cells live an average of only 125 days in circulation. - Since the average number of circulating erythrocytes is some 5 mi...

# تلخيص لاب فسيو ## Erythrocytes - are pliable cells - bend and twist as they pass through the vasculature - Because of this pliability, and because they lack a nucleus, red cells live an average of only 125 days in circulation. - Since the average number of circulating erythrocytes is some 5 million cells per microliter of blood, the adult bone marrow normally forms 2.5 million per second (hundreds of billions of red cells daily) - to replace those being destroyed at the same rate. * Functions of red blood cells: 1. Participate in the transport and release of oxygen and carbon dioxide. 2. Participate in the buffer system of the blood (buffer system). 3. Participate in minor ways in coagulation of the blood. ## Blood Types - All human blood contains erythrocytes, leukocytes, thrombocytes. - But not all human blood is the same type - there are many blood types- if these types are mixed together, the result is an agglutination of red blood cells into clumps (agglutination). - This may travel and become lodged in vasculature causing malfunction of the kidneys, brain, heart, and skeletal muscle. - It's believed that the reason for blood incompatibility is due to the presence of antigens on the surface of red blood cells. ## Antigens - Antigens are chemical substances that when introduced into an animal, will stimulate the animal's immune system to produce antibodies, which react with the antigen in a way that destroys the antigens harmful influence. - When an antigen and antibody of the same type meet, there is a clumping together of the red blood cells, this is known as an agglutination reaction. - Antigens are also known as "agglutinogens" - Antibodies are also known as "agglutinins". ## Blood Groups - The presence or absence of erythrocyte antigens is determined genetically (blood type is inherited). - There are more than 300 types of erythrocyte antigens identified. - Most are weak antigens and therefore rarely trigger an immune response. - However, a few erythrocyte antigens are strongly antigenic causing the recipient to reject donated erythrocytes by agglutination. - There are three main antigens, A, B, and D, that are found on the surface of RBCs. - The corresponding antibodies, normally absent if the antigen is present, are designated as agglutinins: anti-A, anti-B, and anti-D. - This lab will only examine the blood types of the ABO and D (Rh) blood groups. ### ABO Blood Group - **Type A:** Antigen A is present on the surface of the red blood cell. Anti-B antibody is present in the plasma. - **Type B:** Antigen B is present on the surface of the red blood cells. Anti-A antibody is present in the plasma. - **Type AB:** Antigens A and B are both present on the surface of the red blood cell. There are no antibodies in the plasma. - **Type O:** Neither antigen A or B are present on the surface of the red blood cell. Both anti-A and anti-B antibodies are present in the plasma. - If a person with Type B blood is transfused with Type A blood, there will be a reaction as anti-A antibodies will attack the Type A blood cells. - If a person with Type A blood is transfused with Type B blood, there will be a reaction as anti-B antibodies will attack the Type B blood cells. - Type O blood can be transfused to any blood group, it is the **universal donor** as there are no antigens on the blood cells for the antibodies to attack. - Type AB blood can receive blood from any blood group, it is the **universal recipient** as there are no antibodies in the plasma for the red blood cells to be attacked. ### Rh Blood Group - The Rh blood group was first described in 1940 after it was discovered in the monkey. - The presence or absence of the Rh antigen is determined genetically. - The Rh antigen is weak and has little impact on the blood system. - Only The D antigen is important. - **Rh+** means the D antigen is present on the RBC surface. - **Rh-** means the D antigen is absent from the RBC surface. - There are NO anti-D antibodies in those with a Rh+ blood type. - There ARE anti-D antibodies in those with a Rh- blood type. - If a person with Rh- blood is transfused with Rh+ blood, the recipient will develop anti-D antibodies. - If those anti-D antibodies ever come into contact with Rh+ blood again, it will cause a dangerous reaction. ### Transfusion Reactions - There is no reaction when a person with Rh- blood is transfused with Rh- blood, as the recipient's body does not recognize the blood as being foreign. - A wide-spread agglutination occurs when Rh+ blood is transfused with Rh- blood as the donor’s cells are agglutinated (clumped) by the recipient's anti-D antibodies. - This can have serious complications such as shock, anxiety, difficulty in breathing, flushing in the face, pain in the chest and neck.