hematologyagents1 Flashcards
(28 cards)
what is hemostasis
is a physiological process that haltws bleeding that involves the following systems. Vasculatreu platelet coagulation antigulation and fibronolyti
name the antiplatelet drugs
aspirin and dipyridamole, P2y12 receptor antaonists, glycoprotein GP2b 3a antagonists, and patelet thrombin recport antagonists.
what is the importance of collagen and vonwilderbrand factor
not normally found in the blood but with injury it will bind and cause caugolation
what binds vonwilderbrand and collagen
Gp1B and and GP 1A
what binds to fibrongen
GP2b and3a ill bind fibrinogin when activated allowing the platelests to aggragate and coagulate.
what does a plateate that is directly teathard to the site of injury release to activate other plateletes
ADP TXA and 5-HT
what do the intrinsic and extrinsic coagulation pathways converge on
convertin prothrombin to thrombin
what does thrombin do
converts fibrinogin to fibrin and can bind to platelles and active the protease activated receptor PAR
tell me the intrinsic system
12-11-9-common factor 10
tell me about the extrinsic system
7 directly acts on factor 10
tell me about the common system
10 activated by either pathway -10a and 5a -prothrombin to thrombin and that leads to fibrinogin to fibrin and thrombin also does 13- 13a to stable fibrin clot
how does antithrombin work
inactivates factor 10a
how does thrombin work as an anticoagulant
decrase futher thrombine production, activates protien c and degrades facto 5 and factor 8
how does plaminogin get activated
tPA converts it and is relaesd by the endothelium cells
what do the antiplatelet drugs do
work on stopping platelet aggregation
what do the antocoagulation do
work on thrombus
why are anticoagulates used for
to prevent venous thrombosis and thromboembilism
how does heparin sulfate work
binds to antithrombin to increase inhibition of factor Xa and thrombin. A specific sequence of pentasaccharide will bind to antithrombin causing it to have a higher affinity for thrombin, it can also increase the AT induced inhibition by acting as a molecular bridge and bringing it into close contact only longer molecules can do this.
tell me about heparin
has to be used intravenously short half life 90 min so inejected every hours, and is effected by binding to other protein and is unique from person to person so no good fixed dose.
how is heparin cleared
non saturate involving liver and kidneys and a repaid process of binding to and being taken up by endothelial cells this can be saturated. So t1/2=0.693x Vd/CL so aoo units per kg is aout 1 hour 400 is 2.5 and 800 is 5 hours.
what is the activated partial thromboplastin time
how long it takes for your blood to coagulate,
what are the side effects of heparin
bleeding even in normal range, usually can be treated by stopping dose but if its bad use protamine sulfate. Also long term use can lead to osteoperosis. And thrombocytopenia
what is type 1 thrombocytopenia
not enough thrombocytes in the blood, but type one is mild and will return on its own.
what is type 2 thrombocytopenia
uncommon but mortality high, immune response to heparin PF4 complex so antibodies bind to platelets and activate them and then they are cleared by macrophages can cause thrombosis.
