| A | B |
|---|
| the local stoppage of blood flow involves * | 1. vascular wall w/ lining endothelium 2. platelets 3. coagulation protiens |
| primary hemostasis | assd with platelets and blood vessels |
| secondary hemostasis | assd with coagulation protiens |
| normal hemostases (events) | 1. vasoconstriction (arterioles) 2. exp of subendo CT 3. coag sequence activated 4. perm hemostatic plug |
| function of endothelial cell | modulate aspects of hemostasis-coagulation system; both anti/prothrombotic properties |
| prostacyclin (PGI2) | inhibits platelet aggregation and adhesion; antiplatelet effect of ECs |
| thrombomodulin | binds thrombin ->anticoag. effect of ECs ;capable of activating protein C |
| platelets | cell fragments from megakaryocyte |
| alpha granules | in platelets; membranes contain P-selectin |
| products found in alpha granules | fibrinogen, fibronectin, factors V and VII, platelet factor 4, growth factor |
| types of granules found in platelets | alpha and electron dense |
| electron dense bodies | storage sites for nonmetabolic pool of ADP/ATP, Ca++, histamine, serotonin, epinephrine |
| von Willebrand's factor | molecular bridge between platelets and collagen, acts thru glycoprotein receptors |
| platelet attatchment needs | exposed subendothelial collagen, vWF |
| substance exposed on the platelet surface when the platelet bcms activated | phospholipin complex |
| purpose of phospholipin complex | provide site on platelet surf. where coag. factors and Ca++ can bind |
| what happens when Ca++ and coag.factors bind to platelets | intrinsic pathway is activated |
| three imp. stimuli for platelet aggregation | ADP, thomboxane A2, thrombin |
| reversible | primary hemostatic plug |
| irreversible | secondary hemostatic plug |
| ADP + thromboxane A2 + thrombin -> ? | increased platelet aggreg., secondary plug (->platelet contracture (consolidation, viscous metamorphosis) |
| ADP + thromboxane A2 -> ? | platelet aggregation and primary plug |
| prothrombic property of platelets can be induced by | cytokines (IL-1, TNF), bacterial endotoxins |
| ptothrombic binding sites on platelets are for *** | activated forme os IX and X |
| prothrombotic substance secreted by platelets | inhibitor for tissue plasminogen activator |
| what binds to platelet glycoprotien receptors and enhances aggregation | fibrinogen |
| intrinsic pathway | surface contact, exp of subEC collagen, prekallikrein, HMW kininogen |
| extrinsic pathway | tissue damage |
| what starts the final common pathway? | factor X |
| final common pathway | convergence of intrincic and extrinsic pathway |
| soluble proenzymes -> activated enzymes -> thrombin prod. -> soluble fibrinogen -> insoluble fibrin | coagulation cascade |
| needed for liver to convert glutamyl residues to gammacarboxyglutamates | vit K |
| vit K dep clotting factors | II, VII, IV, X |
| inhibitor of vit K activity | Warfarin (coumadin) |
| factors that naturally inhibit fibrin clot formation naturally | antithrombinIII(AT III), protein C, protein S |
| required by antithrombinIII to produce effective anticoag. | heparin or heparin-like protiens |
| AT-III forms a 1:1 complex with * | thrombin |
| AT III has inhib. activity against **** | Xa, XIIa, XIa, and IX |
| factors that decrease AT III levels | preg., oral contraceptives, ext. malignancy, septicemia, after major surgery, autosomal domin. disorder |
| factors inactivated by protien C | V, VIII |
| Protein C circulates as | inactive zymogen |
| protein C is activated by *** | thrombin n the presence of thrombomodulin |
| vit K dep cofactor for protein C | protein S |
| protein D increases production of *** | tissue plasminogen activator (t-PA) |
| breaks down fibrin and reduces fibrin polymerization | fibrinolytic system |
| substances capable of converting plasminogen to plasmin | streptokinase and urokinase, t-PA, factor XIIa, kallikrein, HMW kinninogen |
| interfere with polymerization of fibrin monomer | fibrin split products |
| polymerization of fibrin monomer | causes clotting |
| attacks fibrin clot and forms fibrin split products | plasmin |
