1. Lymphocytes Agranulocyte 20-45% of WBCs Spherical, dark-staining nucleus Thin rim of blue staining cytoplasm Each lymphocyte recognizes and acts against a specific antigen
4. Hemostasis means prevention of blood loss and this achieved by: Vascular constriction Formation of a platelet plug Formation of blood clot Growth of fibrous tissue into the blood clot Hemostasis
5. After blood vessel has been cut, the smooth muscle wall contract; this immediately reduces the flow of blood from the ruptured vessel Vascular Constriction
6. Platelets or thrombocytes Formed in the bone marrow from megakaryocytes Do not have nuclei Function in the clotting process. Normal value – 150,000 to 300,000/cubic millimeter. It has a half life in the blood of 8 – 12 days, its functional process run out over several weeks Formation of platelet plug
8. Contractile protein thrombosthenin that can cause the platelet to contract Endoplasmic reticulum that store Calcium ions Mitochondria capable of forming ATP Enzymes that can synthesize prostaglandins which involves in local tissue reactions Contain fibrin stabilizing factor Growth factors that causes vascular cells to grow and multiply Platelet functional characteristics
9. Platelet begin to swell and assume irregular forms when comes in contact with collagen fibers They become sticky so that they adhere to collagen in the tissue They secrete ADP and form thromboxane which activate nearby platelets The damaged vascular wall activates increasing numbers of platelets thus forming platelet plug. (In small vessels the platelet plug is all that is necessary to stop the bleeding). Mechanism of platelet plug
10. Platelet Plug Formation Exposed collagen binds and activate platelets Release of platelet factors Attract more platelets Aggregate into platelet plug
11. Blood coagulation take place in three steps As result of rupture blood vessels, formation of prothrombin activator (protein manufacture in the liver) Conversion of prothrombin to thrombin in the presence of calcium The thrombin acts as enzyme to convert fibrinogen (blood protein) into fibrin fibers that enmesh platelet, blood cells and plasma to form clot Note: vitamin K is required by liver for formation of prothrombin Blood coagulation in the ruptured vessel
15. Prothrombin activator is generally formed in two ways Extrinsic pathway (begins with trauma to the vascular wall) Intrinsic pathway (begin with the blood) Initiation of coagulation
17. Preventing blood clotting in vascular system is Smoothness of the endothelial cell surface Layer of glycocalyx on the endothelium Protein bound with the endothelial membrane thrombomodulin which binds thrombin Prevention of blood clotting in the vascular system
18. The most important anticoagulant in the blood Fibrin fibers Antithrombin III or antithrombin-heparin cofactor Both fibrin fibers and antithrombin acts as antithrombin About 85-90% of thrombin becomes adsorbed to the fibrin fibers The thrombin that does not adsorb combines with antithrombin III which block the effect of thrombin Antithrombin action of fibrin and antithrombin III
19. Heparin is anticoagulant, low concentration in the blood Effectiveness of antithrombin III increases when it combines with heparin Heparin is formed by basophilic and mast cell Heparin
20. Plasma protein contain euglobulin called plasminogen when activated becomes plasmin Plasmin resemble trypsin Plasmin digest fibrin fibers and other protein coagulants Plasmin caused lysis of a clot Fibrinolysis of blood clot - plasmin
21. Injured tissue release activator called tissue plasminogen activator (t-PA) which convert plasminogen to plasmin Activation of plasminogen
25. Albumin Helps control osmotic pressure Helps control diffusion of water Globulin Includes antibodies (Abs) Transport proteins (lipids, iron, copper, etc.) Fibrinogen Involved in clotting Plasma proteins
26. All the albumin and fibrinogen and 50 – 80% of globulin are formed in the liver The reminder of the globulin are formed in the lymphoid tissues Formation of the plasma proteins
27. Normal values Total protein: 4.2 - 5.6 g/dl Albumin: 2.3 - 3.5 g/dl Globulin: 1.9 – 2.1 g/dl