BL- Introduction to Hemostasis Flashcards
Pro teases of the clotting path way are
Prekallikrein 12 11 9 7 10 2 13*
*=not serine
Factor X is at _____
the cross roads
Factor XIII-
A transglutaminase: forms amide bonds between specific lysine and glutamine residues of fibrin to make a stable____
clot
Cofactors of the clotting path way are
HMWK
TF
VIII
V
These speed up the reaction
Prekallikrein 12 11 9 7 10 2 13 These are all
Proteases
Lack intrinsic enzymatic activity
Act as receptors for other components of enzyme complexes, to speed reactions several hundred to several thousand-fold
Cofactors
Fibrinogen of the clotting path way are
Factor I (Fibrin) *makes the actual clot
HMWK TF VIII V are?
Cofactors
_______requires the interaction of platelets, coagulation and fibrinolytic factors, endothelium, proinflammatory and anti-inflammatory mediators, and leukocytes
Hemostasis
Clot formation is typically initiated by vascular injury, in which a platelet plug forms and is reinforced with ______ produced via the extrinsic pathway
fibrin
Coagulation Factors 1
I Fibrinogen
Cofactors
Lack intrinsic enzymatic activity
Act as receptors for other components of enzyme complexes, to speed reactions several hundred to several thousand-fold
Coagulation Factors 2
II Prothrombin
Coagulation Factors 3
III Thromboplastin
Coagulation Factors 5
Proaccelerin
Coagulation Factors 7
Proconvertin
Coagulation Factors 8
Antihemophilic
Coagulation Factors 9
Christmas
Coagulation Factors 11
Plasma thromboplastin antecedent
Coagulation Factors 13
Fibrin stabilizing
Coagulation Factors IV
Calcium
Prothrombin + Thromboplastin + Calcium = Thrombin
Fibrinogen + Thrombin = Fibrin
Two-step process of coagulation:
The Prothrombin time
measures of prothrombin ratio (PR) and international normalized ratio (INR) are measures of the extrinsic pathway of coagulation. This test is also called “ProTime INR”
Almost all blood factors are made in the:
liver
If this isn’t functioning well, you become coagulopathic
blood factors NOT made by the liver
Tissue factor
Factor VIII
Von Willebrand factor
Two-step process of coagulation:
Prothrombin + Thromboplastin + Calcium = Thrombin
Fibrinogen + Thrombin = Fibrin
Biliary obstruction leads to vitamin K deficiency due to
fat malabsorption
Vitamin K eventually isolated as the factor needed to ______ the bleeding problem
prevent
“K” for “Koagulation”
Vitamin K dependent factors
Factor IX Factor VII Factor X Factor II (Thrombin) Protein C, Protein S
Reasons newborns are prone to develop Hemorrhagic disease of the newborn
Vitamin K deficiency
~Decreased stores
~Low levels in breast milk
~Developing gut flora
Vitamin K required for _________ of several coagulation proteins in the liver
post translational modification
PT test is useful for
Coagulopathy associated with jaundice
Hemorrhagic disease of the newborn
Factor IX Factor VII Factor X Factor II (Thrombin) Protein C, Protein S these are all?
Vitamin K dependent factors
Factors II, VII, IX, X, Protein C, Protein S
Coagulopathy associated with jaundice
Hemorrhagic disease of the newborn
PT test useful
The Activated Partial Thromboplastin time (APTT)
activated partial thromboplastin time
characterizes blood coagulation.
PTT is a performance indicator of the efficacy of both the “intrinsic” (now referred to as the contact activation pathway) and the common coagulation pathways.
It is used in conjunction with the prothrombin time (PT) which measures the extrinsic pathway
Vitamin K dependent factors are located?
Centrally in the pathway (around 10)
PT is a problem in ______ pts
hemophiliac patients
hemophiliac patients are deficient in
factor 13 (a) or 9 (b)
Vitamin K dependent factors
Factors II, VII, IX, X, Protein C, Protein S
Use of the _____led to discovery of the intrinsic pathway factors
APTT
Deficiency of __________ not associated with bleeding
Prekallikrein
Factor XII
HMWK
Coagulation occurs in three phases
Initiation
Amplification
Propagation
Abnormal factors in the _____ pathway will lead to an abnormal ATPP
intrinsic
Initiation steps (1)
Tissue Factor exposed
Factor 7a binds TF
Binds Factor 10 (extrinic tenase)–>10a
Factor 9 can also be activated
extrinic tenase activates
factors 9 and 10
Initiation steps (2)
10a binds–>5a binds–>factor 2
OR
10a binds –> 2
2 leads to 2a leads to amplification
2 leads to 2a leads to:
amplification
Thrombin (2) activates
Factor 11* important
and
Factor XIa
VIIIa
Va