Physiology Part 3 PDF

‫فسيولوجي‬ ‫‪Dr : NOOR‬‬  Platelets formation in bone marrow from megakaryocytes. ////no nucleus Life span 5-9 days function hemostasis (stoppage of bleeding) by forming platelet plugs Hemos...

‫فسيولوجي‬ ‫‪Dr : NOOR‬‬  Platelets formation in bone marrow from megakaryocytes. ////no nucleus Life span 5-9 days function hemostasis (stoppage of bleeding) by forming platelet plugs Hemostasis :prevent hemorrhage 1. Vasoconstriction: contraction of the smooth muscle of the vessel wall, (spasm) 2. platelet aggregation :form a platelet plug. (temporary). 3. Coagulation : by clotting factors that synthesized in the liver. platelets release Thromboplastinogenase turn thromboplastinogen into thromboplastin. Thromboplastin convert prothrombin into thrombin. Thrombin convert fibrinogen to fibrin. The fibrin form a clot. extrinsic pathway intrinsic pathway rapid slower tissue damage takes place. inner walls of blood vessels are damaged. ✓ ‫ملحوظه‬red blood cell contains antigens ✓ The antibodies are specific to certain antigens. ✓ if the baby is RhD positive and maternal and fetal blood come into contact during pregnancy or delivery, this can be prevented by anti-D Immune system ✓ cells, enzymes and proteins providing protection against infections, ✓ destruction of malignant cells immunity ability of the body to resist infection  Innate immunity /acquired at birth Adaptive or Acquired immunity specific immunity passive immunity Active ,responds to known, organisms about 3-6 months; remember a immunological threat [memory} Rapid but short duration Slow but long duration lymphocytes ,lymphatic system. The secondary response occurs on subsequent exposure to the same antigen Antibodies (Ab) are immunoglobulins by plasma B cells. bind to particular antigens. There are the five types of antibodies. Active immunity Passive immunity when the person makes a response to an occurs when the person is given antibodies. antigen and produces antibodies of his own