NUR 612- Disorders of Hemostasis Test Questions and Correct Answers

Describe the three stages of hemostasis. 1. Vessel spasm: constrict/reduce blood flow. Prostaglandin Thromboxane A2 helps mediate this process. 2. Formation of the platelet plug: plts are activated by cytokines and by contact with collagen. They become sticky and attract more plts. 3. Blood coagulation/development of insoluble fibrin clot: Fibrinogen is converted into fibrin, forming a clot with RBCs/Plts. Bleeding stops. Describe the purpose of blood coagulation. An orderly way to stop bleeding. It maintains the integrity of the vascular department. State the function of clot retraction and clot dissolution. Clot retraction and clot dissolution are also significant to hemostasis. The process involves the interaction of substrates, enzymes, protein cofactors, and calcium ions that circulate in the blood or are released from platelets and cells in the vessel wall. Fibrinolysis initiated by plasminogen Plasminogen is converted to plasmin that works to dissolve the clot. What proteins are important in the process of the negative feedback control of clotting? Protein S and C. Protein S, another plasma protein, accelerates the action of protein C. Both protein S and protein C are important as anticoagulants. Decribe how heparin and coumadin work. Heparin affects factor X without having a large effect on other clotting factors. Cannot be absorbed GI, must be SQ or IV. Coumadin is oral and affects vit K production. There are several clotting factors including factor X, factor II (thrombin), prothrombin, and protein C that are vit K dependent. Compare normal and abnormal clotting. Hypercoagulabity causes excessive clotting and contributes to thrombus formation. It results from conditions that enhance platelet numbers/activity. Describe the causes and effects of increased platelet function. There are several known conditions that increase platelet activity: Atherosclerosis, Diabetes mellitus, Smoking, Elevated blood lipid and cholesterol levels, Increased platelet levels, Pregnancy,