Inhibitors Of Clotting Flashcards
List the inhibitors of clotting
Heparin and antithrombin
Anti coagulant
List the anticoagulant drugs
-Aspirin
-Warfarin
-Dicumarol
-Streptokinase
-Coumarins
-Genetically engineered (recombinant) tissue-plasminogen activator (rt-PA)
-dilute sterile solution of a citrate or an oxalate salt is added to collected blood.
Anticoagulants
•As many as 35 compounds may be required for blood coagulation.
•Such a complex system of checks and balances is necessary to prevent clotting when there is no bleeding.
•An unwanted clot in a blood vessel that cuts off the blood supply to a vital organ is one of the body’s worst enemies.
Most of the body’s anticoagulant substances circulate within the blood, and the blood vessels themselves help prevent clotting.
•The blood vessels contribute in two ways.
•First, the ————- normally prevents activation of the intrinsic clotting mechanism.
•Second, a ———-attached to the inner walls repels the clotting factors, preventing the initiation of clotting.
•Injury to a blood vessel removes both of these safeguards.
•The ———and the—-layer beneath the smooth endothelium initiate the platelet phase of hemostasis.
•If the platelet plug that forms cannot stop the loss of blood, factor —- is activated, along with the rest of the intrinsic pathway.
Most of the body’s anticoagulant substances circulate within the blood, and the blood vessels themselves help prevent clotting.
•The blood vessels contribute in two ways.
•First, the smoothness of the inner walls normally prevents activation of the intrinsic clotting mechanism.
•Second, a thin layer of negatively charged protein molecules attached to the inner walls repels the clotting factors, preventing the initiation of clotting.
•Injury to a blood vessel removes both of these safeguards.
•The rough damaged wall of the vessel and the negatively charged collagen layer beneath the smooth endothelium initiate the platelet phase of hemostasis.
•If the platelet plug that forms cannot stop the loss of blood, factor XII is activated, along with the rest of the intrinsic pathway.
Heparin and antithrombin:
•One of the most powerful anticoagulants in the blood is ——, a polysaccharide produced by mast cells and basophils.
•Heparin is concentrated mostly in the —- and —-.
•Minute quantities of heparin in normal circulating blood also prevent clotting by combining with the ——-cofactor (also called antithrombin or antithrombin III) to induce the co-factor to combine with thrombin —— times more rapidly than usual.
•This rapid binding to thrombin removes it almost instantly from the bloodstream and makes clotting almost impossible.
•Without heparin, antithrombin-heparin cofactor binds to thrombin molecule for molecule, removing it from the blood in about —min.
The combination of heparin and antithrombin-heparin cofactor also reacts with several clotting factors in the extrinsic and intrinsic pathways, further inhibiting blood clotting.
•Thrombin itself acts as an ———.
•When its concentration becomes too high, it destroys factor —- to prevent clotting.
Heparin and antithrombin:
•One of the most powerful anticoagulants in the blood is heparin, a polysaccharide produced by mast cells and basophils.
•Heparin is concentrated mostly in the liver and lungs.
•Minute quantities of heparin in normal circulating blood also prevent clotting by combining with the antithrombin-heparin cofactor (also called antithrombin or antithrombin III) to induce the co-factor to combine with thrombin 1000 times more rapidly than usual.
•This rapid binding to thrombin removes it almost instantly from the bloodstream and makes clotting almost impossible.
•Without heparin, antithrombin-heparin cofactor binds to thrombin molecule for molecule, removing it from the blood in about 15min.
The combination of heparin and antithrombin-heparin cofactor also reacts with several clotting factors in the extrinsic and intrinsic pathways, further inhibiting blood clotting.
•Thrombin itself acts as an anticoagulant.
•When its concentration becomes too high, it destroys factor VIII to prevent clotting.
heparin, a polysaccharide produced by —- and —-.
heparin, a polysaccharide produced by mast cells and basophils.
—— (also called——), -prevents platelets from sticking together to form a plug and inhibits the release of clot-promoting substances from platelets
•—— digests the fibrin threads of a and is released by certain streptococcal bacteria.
•Streptokinase activates —— to speed fibrinolysis.
• used to dissolve blood clots (thrombi) in veins and arteries.
•Streptokinase also helps dissolve the fibrin threads in a blood clot by converting plasminogen into ——-, the fibrin-destroying enzyme.
•————is effective in dissolving intravascular blood clots when delivered directly to a clotted area through a catheter.
•For example, if rt. PA is used within the first several hours after a blood clot forms in a coronary artery, the heart is often spared a serious damage.
Aspirin (acetylsalicylic acid), -prevents platelets from sticking together to form a plug and inhibits the release of clot-promoting substances from platelets
•Streptokinase digests the fibrin threads of a and is released by certain streptococcal bacteria.
•Streptokinase activates plasminogen to speed fibrinolysis.
• used to dissolve blood clots (thrombi) in veins and arteries.
•Streptokinase also helps dissolve the fibrin threads in a blood clot by converting plasminogen into plasmin, the fibrin-destroying enzyme.
•Genetically engineered (recombinant) tissue-plasminogen activator (rt-PA) is effective in dissolving intravascular blood clots when delivered directly to a clotted area through a catheter.
•For example, if rt. PA is used within the first several hours after a blood clot forms in a coronary artery, the heart is often spared a serious damage.
—— is a compound that resembles vitamin K to such an extent that the liver enzymes that form prothrombin will pick up dicumarol instead of vitamin K.
•The anti-coagulatory effect of dicumarol is often used to prevent clotting after surgery.
•Warfarin, coumarins etc
•In addition to being used to remove blood clots and keep blood from coagulating during surgery, anti-coagulant drugs may be necessary to prevent clotting in blood that will be used later for blood transfusions .
•To avoid such clotting, a dilute sterile solution of —— or——salt is added to collected blood.
Dicumarol is a compound that resembles vitamin K to such an extent that the liver enzymes that form prothrombin will pick up dicumarol instead of vitamin K.
•The anti-coagulatory effect of dicumarol is often used to prevent clotting after surgery.
•Warfarin, coumarins etc
•In addition to being used to remove blood clots and keep blood from coagulating during surgery, anti-coagulant drugs may be necessary to prevent clotting in blood that will be used later for blood transfusions.
•To avoid such clotting, a dilute sterile solution of a citrate or an oxalate salt is added to collected blood.
Role of Vitamin K in blood coagulation
•vitamin k, a group of lipophilic and —— vitamin produced by bacteria inhabiting the large intestine, is necessary to form clotting factor — ,—, —, — and protein — as inactive precursors (zymogens) in the liver. although vitamin k is not involved in actual clot formation. It is required for the ——-
Role of Vitamin K in blood coagulation
•vitamin k, a group of lipophilic and hydrophobic vitamin produced by bacteria inhabiting the large intestine, is necessary to form clotting factor II ,VII, IX, X and protein C as inactive precursors (zymogens) in the liver. although vitamin k is not involved in actual clot formation. It is required for the post translational carboxylation (in the ER of the glutamic acid residues of the proteins necessary for blood coagulation.
Complement System
•~—- blood proteins that circulate in inactive
•Called the complement because it helps other —- cells to perform their functions
•Activation unleashes —— chemicals that amplify virtually all aspects of the inflammatory process.
•It can also lyse and kill certain bacteria and other cell types
Complement System
•~20 blood proteins that circulate in inactive
•Called the complement because it helps other immune cells to perform their functions
•Activation unleashes inflammatory chemicals that amplify virtually all aspects of the inflammatory process.
•It can also lyse and kill certain bacteria and other cell types
. —- enzymes keep the vitamin in an active(reduced) state
the liver. Vitamin K reductase enzymes keep the vitamin in an active
