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| What is hemostasis? | The stoppage of bleeding or hemorrhage. |
| What are the components of hemostasis? | Blood Platelets, Endothelial Cells, Plasma Coagulation Factors |
| What are the steps involved in hemostasis? | 1. Compression and Vasoconstriction 2. Formation of a platelet plug 3. Blood Coagulation 4. Clot retraction and thrombus dissolution |
| What is the purpose of vascular spasms? | Reduces blood flow and blood loss |
| What are the stepsw involved in the formation of a platelet plug? | 1. Adherence - binding of receptor platelets 2. Aggregation - Platelets stick to collagen fibers 3. Secretion - releases ADP, thromboxane, and collagen |
| What plays a role in clot formation as well as clot dissolution? | Thrombin |
| What organ is primarily responsible for the formation of coagulation factors? | Liver |
| Where do thrombocytes originate from? | From megakaryocytes in the bone marrow |
| What vitamin is required for the activation of some coagulation factors? | Vitamin K |
| How long does it take for the formation of a blood clot to begin in a severe trauma? | 15-20 seconds |
| How long does it take for the formation of a blood clot to begin in a minor trauma? | 1-2 minutes |
| What is the clot initiated by? | Bllod proteins, and activator substanes from platelets and the vascualr wall |
| How long does it take for the clot to be formed? | 3-6 minutes |
| What time does clot retraction occur? | 20 min - 1 hour |
| What forms connective tisue within the clot? | Fibroblasts |
| What is the size of platelets? | 2-4 micrometer |
| What is the half-life of a platelet? | 8-12 Days |
| What organ is primarily responsible for eliminating platelets? | Spleen - by the tissue macrophage system |
| True or False, platelets contain a nucleus? | False |
| True or False, platelets can reproduce? | False |
| What is the surface of platelet cell membrane composed of? | Glycoproteins - avoids sticking to the endothelium |
| What are procoaggulants? | substances that promote coagulation |
| What are anticoagulants? | substances that inhibit coagulation |
| What is the role of prothrombin activator? | Catalyzes the conversion of prothrombin into thrombin |
| What does thrombin do? | It acts as an enzyme to convert fibrinogen into fibrin fibers |
| True or False fibrinogen has a high molecular weight? | True - 340,000 |
| True or False, platelets are necessary for clot retraction? | True |
| Clotting factors are dependent on what vitamin? | Vit K |
| List the types clotting factors? | 1. Prothrombin 2. Protein C 3. Factor VII 4. Factor IX 5. Factor X |
| How many pathways are there in the coagulation cascade? | 2, Extrinsic Pathway - Tissue Damage & Intrinsic Pathway - Endothelial damage |
| What is necessary for the activation of both pathways of the Coagulation Cascade? | Phospholipids |
| What all is involoved in Clot retraction? | 1. Prostacyclin (PGI2) 2. Tissue Plasminogen Activator (TPA) 3. Plasmin 4. Thrombin 5. Protein C and its cofactor protein S 6. Antithrombin III 7. Heparin |
| True or False, Strokes and Embolisms are associated w/ abnormalities in Protein C and S, Antithrombin III, and Plasminogen? | True |
| Name 3 causes of excessive bleeding? | 1. Vit. k deficeincy 2. Hemophilia 3. Thrombocytopenia |
| What is a thrombus? | an abnormal clot that develops in the blood vessel |
| What is an emboli? | A free flowing clot |
| What are the 3 causes of thromboembolic conditions? | 1. Roughened Endothelial surface of a vessel 2. slow flowing blood 3. DIC - Disseminated Intravascular Coagulation |
| What are the 2 types of anticoagulants? | Heparin and Coumarins |
| What are the 3 types of Blood Coagulation Tests? | 1. Bleeding Time 2. Clotting Time 3. Prothrombin Time |
