Coag ppt Flashcards
4 statges of hemostasis
HUGE SLIDE BUT THE BASIS AND INTRO INTO ALL THAT FOLLOWS
- VASCULAR CONSTRICTION- limits the flow of blood to the area of injury
- PLATELETS become ACTIVATED by thrombin and aggregate at the site if injury (temp loose PLATELET PLUG). Fibrinogen is responsible for stimulating platelet clumping (platelets bind to collagen that becomes exposed following rupture of the endothelial lining of vessles)
- Activated platelets release ADENOSINE-5’-DIPHOSPHATE (ADP) and TXA2 (which activates additional platelets), SEROTONIN, PHOSPHOLIPIDS, LIPOPROTEINS, and other proteins important for the coagulation cascade. Activated platelets change their shape to accomodate the formation of the plug.
- to insure stability of the initial loose platelet plug, a FIBRIN MESH (CLOT), forms and entraps the plug. if the plug contains only platelets it is termed WHITE THROMBUS, if red blood cells are present it is called RED THROMBUS.
The clot must be dissolved in order for normal blood flow to resume following tissue repair. the dissolution of the clot occures through the action of PLASMIN
test that knowledge
initial phase if hemostasis
vascular constriction
to test that knowledge
platelets become activated by what?
thrombin
to test that knowledge
what is responsible for stimulating platelet clumping
fibrinogen
to test that knowledge
activated platelets release what?
(6)
ADP
TXA2
Serotonin
Phospholipids
Lipoproteins
other proteins
to test that knowledge
which protein released by activated proteins, activates additional platelets
TXA2
to test that knowledge
what forms to entrap the plug to insure stability
Fibrin mesh (clot)
to test that knowledge
- If the plug contains only platelets it is called what?
- If it containd RBC ot is called what
- white thrombus
- red thrombus
to test that knowledge
dissolution of the clot occurs through the action of what?
plasmin
Whooooo made it time for an easy question to make you feel smart again!
1+1=?
2
picture time
now that you feel better. draw me a pic representation of what you want your edothelial layer to look like with a break and blood in the middle
keep this we’ll expand
Physiology, pathophysiology, and pharmacology of hemostasis
what is the patho for adhesion of platelets
- Damage to endothelial surface → subendothelial collagen exposure
- production/release of vWF form endothelial cells
- vWF anchors platelets to subendothelial collagen vascular wall
vWF= Von Willebrad factor
you now know the adhesion of plateletes draw it!!!
- Damage to endothelial surface → subendothelial collagen exposure
- production/release of vWF from endothelial cells
- vWF anchors platelets to subendothelial collagen vascular wall
Hint expand your 1st pic
What is the most common inherited coagulation defect
Von Willebrands Disease
what is tx for Von Willebrands disease
DDAVP- it releases vWF from endothelial cells
or
Give FFP
Physiology, pathophysiology, and pharmacology of hemostasis
patho of the activation of plateletes
- prothrombin → thrombin (IIa) which activates platelets
- Shape changes and realease of mediators (TXA2 and ADP)
- TXA2 and ADP promote platelet aggregation
now that you know the patho for activation of platelets draw it!!!
- prothrombin → thrombin (IIa) which activates platelets
- Shape changes and realease of mediators (TXA2 and ADP)
- TXA2 and ADP promote platelet aggregation
Physiology, pathophysiology, and pharmacology of hemostasis
What is the patho for aggregation of platelets
- TXA2 and ADP “uncover” fibrinogen receptor (GPIIb/IIIa)
- this allows fibrinogen (I) to bind to the receptor and further aggregate platelets
- TXA2 and ADP “uncover” fibrinogen receptor (GPIIb/IIIa)
- this allows fibrinogen (I) to bind to the receptor and further aggregate platelets
yep your going to draw it!!! try putting all of the drawings together
After platelets aggregate , __1__ is woven into plateets and cross-linked (water soluble >stable)
the cross linkage requires fibrin stabilizing factor __2__
- fibrin
- XIII
mechanism of action aspirin and NSAID’s
COX 1 inhibition: reduction in TXA2
All procoagulants (clotting factors) are produced in the ___1___, with the exception of what 3? and where are they produced?
- liver
- tissue factor or thromboplastin (III)- released from traumatized cells
- Ca++(IV)- diet
- vWF (VIII:vWF)- vascular endothelial cells
whhat are the vit K dependent factors
- II
- VII
- IX
- X
- protein C
- Protein S
what are the roman numerics for the following clotting factors
- fibrinogen
- prothrombin
- tissue factor/thromboplastin
- Von Willibrands factor
- fibrinogen- I
- prothrombin- II
- tissue factor/thromboplastin III
- Von Willibrands factor VIII:vWF
tissue factor/thromboplastin (III) comes from where?
Vascular wall and extravascular cell memerane; released from traumatized cells
clotting cascade TISSUE FACTOR PATHWAY (Extrinsic)
(Factor III)
- Damage occurs from outside of blood vessel → triggers release of tissue factor
- Tissue factor comes in contact with factor VII
- Complexed with Ca++ on platelet → activates factor X
clotting cascade TISSUE FACTOR PATHWAY (Extrinsic)
- Damage occurs from outside of blood vessel → triggers release of tissue factor
- Tissue factor comes in contact with factor VII
- Complexed with Ca++ on platelet → activates factor X
put this whole cascasde into a picture
what is the primary physiologic initiator of coagulation
(in the extrinsic pathway)
tissue factor
the tissua factor pathway (extrinsic pathway) is measured by what?
PT test
how to remember the Extrensiv pathway
you can buy the extrinsic pathway for $0.37 (III, VII)
Clotting cascade Contact activation pathway (Intrinsic)
- Initiated when there is trauma to the vessel itself or exposure of blood to collagen
- Activation of XII→ XI→IX when complexed with platelet surface with factor VIII:C and Ca++ → factor X
Clotting cascade Contact activation pathway (Intrinsic)
- Initiated when there is trauma to the vessel itself or exposure of blood to collagen
- Activation of XII→ XI→IX when complexed with platelet surface with factor VIII:C and Ca++ → factor X
make it into a diagram
the contact activation pathway (Intrinsic) is measured by what?
PTT
how to remember the intrinsic pathway
you can buy the intrinsic pathway for $12 (XII) or $11.98 (XI, IX, VIII)
clotting cascade Final common pathway
- Activatio startes with X -> V -> II -> I -> XIII
- Thrombin converts finbrinogen (I) to fibrin and in the pressence of XIII, fibrin cross-linking occurs
- the new clot is formed now
clotting cascade Final common pathway
- Activatio startes with X -> V -> II -> I -> XIII
- Thrombin converts finbrinogen (I) to fibrin and in the pressence of XIII, fibrin cross-linking occurs
- the new clot is formed now
now since we know everything put it all together in one big ass diagram that encompasses the final common pathway
how to remember the clotting cascade common pathway?
the common pathway can be purchased at 5 (V) or 10 (X) for 1 (I) or 2 (II) dollars on the 13th (XIII) of each month
Hemostasis: in short
5 steps down and dirty
- vasoconstriction
- formation on platelet plug
- activation of coagulation cascade
- Formation of blood clot
- Clot retraction and dissolution (fibrinolysis)
What is antithrombin III
produced in the liver and neutralizes the final common pathway IIa & Xa and intrinsic factors IX, XIa, & XIIa
antithrombin III
- strongly inhibits what factors
and
- partially inhibits what factors
- final common pathway IIa and Xa
- intrinsic IXa, XIa & XIIa
antithrombin III os a required cofactor for what?
Heparin
Heparin binds to antithrombin III and enhances AT III by ______ x’s
1000
which anticoagulant drug is an inhibitor of clotting factor synthesis include what drug
Coumadin