logging in or signing up Coagulation Pathway lelavardee Download Post to : URL : Related Presentations : Let's Connect Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Copy embed code: Embed: Flash iPad Dynamic Copy Does not support media & animations Automatically changes to Flash or non-Flash embed WordPress Embed Customize Embed URL: Copy Thumbnail: Copy The presentation is successfully added In Your Favorites. Views: 20271 Category: Education License: All Rights Reserved Like it (16) Dislike it (14) Added: January 01, 2009 This Presentation is Public Favorites: 8 Presentation Description No description available. Comments Posting comment... By: faseehuddin (31 month(s) ago) useful Saving..... Post Reply Close Saving..... Edit Comment Close By: mfarwan (34 month(s) ago) goooooooooooooooooooooooooooooooood Saving..... Post Reply Close Saving..... Edit Comment Close By: stefanica (38 month(s) ago) very nice and dinamic presentation thank you Saving..... 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See all Premium member Presentation Transcript COAGULATION PATHWAY : COAGULATION PATHWAY Slide 2: Vessel injury vasocontriction Reduced Blood flow Collogen exposure Platelet Release reaction Primary Haemostatic plug Platelet fusion STABLE HAEMOSTATIC PLUG Factor XII Thrombin fibrin Tissue Thromboplastin Blood Coagulation Normal haemostasis involvesinteraction of : : Normal haemostasis involvesinteraction of : Blood vessels Platelet Coagulation factors Initial arrest of haemorrhage : Initial arrest of haemorrhage Vasoconstriction & elastic recoil of severed blood vessel Formation of platelet plug Coagulation Pathway : Coagulation Pathway Activation of blood clotting factors Fluid blood ? insoluble fibrin clot Coagulation Cascade : Coagulation Cascade • Factors Circulate In Inactive Form – Proenzyme – Procoagulant • Enzymatic Cleavage To Active Form • Remaining Portion Becomes Active Cleavage Enzyme – Serine Protease • “Activated Clotting Factor” – “VIIa” – Cleaves Next Procoagulant Factor Blood vessel injury : Blood vessel injury Platelet adhere to exposed subendothelial tissue - subendothelial microfibrils binds to vWH which binds to pH membrane Ib complex - spherical shape with pseudopods ? Interaction between pHs Platelet activation : Platelet activation Glycoprotein 11b/111a binding pH aggregation Binding with vWF Promoting adhesion Platelet release reaction : Platelet release reaction Collagen exposure Thrombin ADP - lysosomal enzyme Serotonin - b thromboblobulin Fibrinogen - heparin neutralising factor (PF4) Secretion of plt. granules:- Cell membrane : Cell membrane Release thromboxane A2 Potentiate pH aggregation vasoconstriction ADP : ADP Cause platelet to swell Adhesion Result on more release reaction Further plt. aggregation Platelet Procoagulant activity : Platelet Procoagulant activity Exposed membrane phospholipid (PF3) X Xa Prothrombin Thrombin IXa, VIIIa Xa Va Ca++ Blood Coagulation : Blood Coagulation Biological amplification system (lmol X la ? 2x108 mol of fibrin) Circulating precursor Proteolysis Activation Fibrinogen ? fibrin (form stable clot with platelets) Tissue Factor - TF : Tissue Factor - TF not expressed normally disruption of endothelium ? TF expression ? formation of FVII/TF complex ? activation of FVII ? FVIIa/TF FVlla/TF complex : FVlla/TF complex Activate FX & FIX Xa, lla, FVlla, FIXa ? activate FVII (positive feedback) FVlla, TF FXa : FVlla, TF FXa Binds with TFPl ? quarternary complex ? Inhibits further generation of Xa, IXa More Xa in formed : More Xa in formed X Xa - FVIII FVIIIa - FIX FIXa FIXa, FVIIIa Thrombin XIa Thrombin : Thrombin Activate FVII, FV FXI Platelet FXIII Old Coagulation Pathway : Old Coagulation Pathway Extrinsic & intrinsic pathway Able to test the ‘2 pathways’ Able to understand coagulation Fail to represent the true picture Inaccuracy of the old Pathway : Inaccuracy of the old Pathway No clinical problem with deficiency of FXII, prekallikrein or HMWR ( APTT) FXI deficiency – don’t always present with bleeding FVII deficiency ? bleeding (even tho entrisnic pathway is intact) FVII activate FIX, FX TF is a natural constituent of many nonvascular cells Identification of TFPI Coagulation Cascade Newer Thoughts : Coagulation Cascade Newer Thoughts Surface Antigens • Play Role In Activation • Localize Coagulation • Some Factors Need Two Activators • Second “Co-Factor” • Create “Reaction Complex” • Require Phospholipid Surface Coagulation Cascade Testing : Coagulation Cascade Testing Intrinsic and Extrinsic Pathways - Presence of Platelet Phospholipid Needed to Test Intrinsic Pathway Partial Thromboplastin Time Platelet Phospholipid Substitute - Chloroform Extract from Rabbit Brain –Thromboplastin - Reflects Clotting Ability of Intrinsic andCommon Pathway Intrinsic Pathway Test - PTT : Intrinsic Pathway Test - PTT Modified By “Surface Activating Factors – XII & XI “Activated Partial Thromboplastin Time” – Maximum Activation of Contact Factors • XII, XI, Prekallilrein, & High Molecular Weight Kinogen – More Consistent , Reproducible • Eliminates Lengthy Contact Activation Phase • Normals – PTT: 40 – 100 secs (> 120 Abnormal) – aPTT: 25–35 secs Extrinsic Pathway Test : Extrinsic Pathway Test Prothrombin Time– Activity of Factor VII Intrinsic Pathway Factors X, V, II, & I– Addition of Tissue Thromboplastin and Ca+ Time to Clot Formation Slide 36: PREPARED BY PN. BOOB PA INIT 36 ............. sekian .................. You do not have the permission to view this presentation. In order to view it, please contact the author of the presentation.