1. Coagulation

2. Coagulation Blood Clotting
Very complex process
Balance between clotting factors—some promote coagulation and some inhibit it
Normally anticoagulants prevail but in trauma or injury, coagulation factors increase and clotting occurs

3. Process of coagulation when tissue damage occurs
Prothrombin activator produced (depended on calcium)
Prothrombin converted to thrombin
Thrombin acts as an enzyme—causes reaction in fibrinogen
Fibrinogen molecules join forming fibrin

4. Fibrin sticks to the edge of damaged blood vessels and form meshwork for platelets and blood cells—blood clot forms

5. Once the clot appears—promotes more clotting—positive feedback mechanism—thrombin causes more prothrombin—causes more thrombin
Unstable condition
Movement of blood normally prevents massive clot formations

6. Clotting ceases when clot comes in contact with moving blood
Plasma protein is released which digests fibrin threads—most clots dissolve in time
Embolus—dislodged or fragment of clot abnormally in vessel—moves until it becomes lodged in small vessel—interferes with blood flow to the area

9. Blood groups
Antigens
Proteins on rbc membrane surface
A, B, Rh

10. Antibody
a. Proteins in plasma
b. Anti A, Anti B are formed naturally
Rh group
a. Anti Rh does not appear spontaneously—only after exposure

12. ABO Blood Groups Type Antigen Antibody A Anti B B Anti A O None
Anti A, Anti B AB
A and B
none