Drugs Affecting Coagulation
Haemostasis definition✅
Vasoconstriction✅
Temporary platelet plug✅
Blood clotting✅
Retraction✅
Haemophilia✅
Vitamin k deficiency✅
Prostacyclin✅
DVT, VTE and PE`✅
Thrombosis✅
Heparins✅
Hirudins✅
Warfarin✅
Thrombin inhibitors✅
Aspirin ✅
anti-platelet✅
fibrinolysis✅
Haemostasis
Prevents blood loss after damage to a vessel.
There are 4 stages for coagulation.
Vasoconstriction
Smooth muscle contracts/vascular spasm.
Vessel narrows.
Prevents blood loss.
Less blood flows to the area.
Platelets also secrete epinephrine and serotonin which also increases vasoconstriction.
Temporary Platelet plug
Platelets circulate the bloodstream.
When activated they stick together.
Platelets also secrete chemicals that attract other cells, in the clotting process, to the site of
injury.
Von Willebrand Factor (vWf) is secreted by the platelets and subendothelial tissue (when
exposed due to damage).
When damaged the collagen fibres on the subendothelial tissue binds to vWf.
, This anchors the platelets in place.
And causes platelets to secrete more of these chemicals to start the coagulation process.
Positive feedback loop.
ADH= released by platelets to cause them to adhere to each other and show the change in
the platelets in the diagram above.
More is secreted every time platelets adhere=positive feedback
ADH also stimulates thromboxane A2 production which also has platelet aggregation
properties.
Platelet plug is limited to the area of the damaged vessel to prevent unnecessary blood clots.
Blood clotting
A clotting factor cascade.
To form a fibrin clot.
When activated they form peptide bonds.
Intrinsic pathway: 12 activates 11 activates 9 activates 10.
Extrinsic: using calcium, 7 is activated to activate 10.
Thrombin converts fibrinogen to fibrin monomers.
These monomers form fibrin polymers
Which forms a mesh to trap erythrocytes.
Clot Retraction
Plasmin=dissolves the clot
Protein derived from plasminogen.
Breaks down fibrin.
Plasminogen activators are released by different cells to start this process.
Stops blockages for too long.
Haemophilia
Insufficiency in the intrinsic pathway
Due to a reduction of one of the factors
A: loss of factor 8
B: loss of factor 9
Vitamin K deficiency
Certain factors that are used in coagulation are not carboxylated.
This can lead to reduced blood clotting.
Naturally occurring in plants and in the gut
Essential in the formation of clotting factors
Vitamin K activates gamma-glutamyl carboxylate which adds a carboxyl group to allow
calcium ions to bind to the clotting factors to activate them.
Haemostasis definition✅
Vasoconstriction✅
Temporary platelet plug✅
Blood clotting✅
Retraction✅
Haemophilia✅
Vitamin k deficiency✅
Prostacyclin✅
DVT, VTE and PE`✅
Thrombosis✅
Heparins✅
Hirudins✅
Warfarin✅
Thrombin inhibitors✅
Aspirin ✅
anti-platelet✅
fibrinolysis✅
Haemostasis
Prevents blood loss after damage to a vessel.
There are 4 stages for coagulation.
Vasoconstriction
Smooth muscle contracts/vascular spasm.
Vessel narrows.
Prevents blood loss.
Less blood flows to the area.
Platelets also secrete epinephrine and serotonin which also increases vasoconstriction.
Temporary Platelet plug
Platelets circulate the bloodstream.
When activated they stick together.
Platelets also secrete chemicals that attract other cells, in the clotting process, to the site of
injury.
Von Willebrand Factor (vWf) is secreted by the platelets and subendothelial tissue (when
exposed due to damage).
When damaged the collagen fibres on the subendothelial tissue binds to vWf.
, This anchors the platelets in place.
And causes platelets to secrete more of these chemicals to start the coagulation process.
Positive feedback loop.
ADH= released by platelets to cause them to adhere to each other and show the change in
the platelets in the diagram above.
More is secreted every time platelets adhere=positive feedback
ADH also stimulates thromboxane A2 production which also has platelet aggregation
properties.
Platelet plug is limited to the area of the damaged vessel to prevent unnecessary blood clots.
Blood clotting
A clotting factor cascade.
To form a fibrin clot.
When activated they form peptide bonds.
Intrinsic pathway: 12 activates 11 activates 9 activates 10.
Extrinsic: using calcium, 7 is activated to activate 10.
Thrombin converts fibrinogen to fibrin monomers.
These monomers form fibrin polymers
Which forms a mesh to trap erythrocytes.
Clot Retraction
Plasmin=dissolves the clot
Protein derived from plasminogen.
Breaks down fibrin.
Plasminogen activators are released by different cells to start this process.
Stops blockages for too long.
Haemophilia
Insufficiency in the intrinsic pathway
Due to a reduction of one of the factors
A: loss of factor 8
B: loss of factor 9
Vitamin K deficiency
Certain factors that are used in coagulation are not carboxylated.
This can lead to reduced blood clotting.
Naturally occurring in plants and in the gut
Essential in the formation of clotting factors
Vitamin K activates gamma-glutamyl carboxylate which adds a carboxyl group to allow
calcium ions to bind to the clotting factors to activate them.
