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Old 11-15-2010
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Blood How to study coagulation cascade/factors

Hi All,
I try to memorize coagulation cascade and factors long time but without any big success Anyway I mixed up with this...
Could someone give me an idea - how memorize it?
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Old 11-16-2010
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The cascade itself is not that high-yield. You should know, instead, what factors belong to each pathway.

Factors 1, 2 (thrombin), 5, 7, 10 belong to the extrinsic pathway (asses with PT).

All factors except 7, 13 belong to the intrinsic pathway (assess with PTT).

As you can see, factor 7 (VII) is unique to the extrinsic pathway. It's the first factor to be affected in liver disease, and abnormal PT is most sensitive to a defect in this factor.

Factor 13 (XIII) is activated by thrombin (II), and is responsible for cross-linking of fibrin strands. Its deficiency presents at birth by severe umbilical bleeding (AR disease).

Factor 12 (XII), on the other hand, is fibrinolytic. Its deficiency may predispose to thrombosis.

Of course you should also be aware that Protein C and S (activated by vitamin K) are anticoagulants in that they deactivate factor 5 (V) and 8 (VIII).
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Old 11-16-2010
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Warning! Factor4

Q1 Is factor 4 Calcium ion?

Q2 Is this is the one to which heparin binds in
Heprin induced thrombocytopenia?

Q3 Is this factor trapped when v add citrate to blood to prevent clotting in vitro?

plz clarify as this coagulation cascade is driving me crazy
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Old 11-16-2010
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I thought something different. Please tell me if I am wrong.

Extrinsic (tested by PT)
7, [10, 5, 2 (prothrombin), 1 (fibrinogen)]
Affected by liver disease, vitamin K deficiency, warfarin

Intrinsic (tested by PTT)
12, 11, 9, 8 [10, 5, 2, 1]


Also, with regards to coagulation, according to Kaplan, F8 replacement is given in von Willebrand disease if DDAVP is not effective. Why? What is the link between vWF and F8? And why is DDAVP a treatment for both vWD (def. of vWF) and Haem A (def. of F8)?
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Old 11-16-2010
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Quote:
Originally Posted by Haisook View Post
The cascade itself is not that high-yield. You should know, instead, what factors belong to each pathway.

Thank you for answer.
Yes I know, but sometimes in questions you need choose exact number... Anyway I need to memorize "I it is fibrinogen; IV it is Ca++; VIII - antihem A; IX - cristmas f. or antihem B... etc" Also in Kaplan QBook there is explanation that all factors (excl VIII) synthesized in liver but VII affected first and much more because the VII factor has shortest half-life. Actually I didn't understand it clear - because usually we talk about chronic disease, so all factors must be affected (except VIII).
I found a picture in Goljan path, may be it could help me to memorize something in it. I think my brain doesn't see any association with roman numerals


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Old 11-20-2010
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Quote:
Originally Posted by deyneko View Post
Thank you for answer.
Yes I know, but sometimes in questions you need choose exact number... Anyway I need to memorize "I it is fibrinogen; IV it is Ca++; VIII - antihem A; IX - cristmas f. or antihem B... etc" Also in Kaplan QBook there is explanation that all factors (excl VIII) synthesized in liver but VII affected first and much more because the VII factor has shortest half-life. Actually I didn't understand it clear - because usually we talk about chronic disease, so all factors must be affected (except VIII).
I found a picture in Goljan path, may be it could help me to memorize something in it. I think my brain doesn't see any association with roman numerals


Just to add in yours,Remember for startig from 12 (twelve)Intrinsic Path: every alphabet in the end is the start for other..
Like Twelve --> Eleven --> Nine --> Eight
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