quiz blood stuff Flashcards
process of stopping blood loss
Hemostasis
principle mechanism of hemostasis
Blood coagulation
mesh of protein filaments that traps blood’s formed elements to
form a red, gelatinous mass
Blood clot
Fibrin thread
threads that holds the blood cells together and they seal the
wound to prevent loosing of blood
______ become activated upon injury through the extrinsic and intrinsic pathways
Clotting factors
____ present in the blood at all times in their inactive form and produced in the liver
Clotting factors
Vitamin K is required to produce _____( gut flora=Vit k, or from outside)
Clotting factors
CF I
Fibrinogen
CF II
Prothrombin
CF V
Preaccelerin
CF VII
Proconvertin
CF VIII
Antihemophilic factor
Christmas factor
CF IX
CF X
Stuart-Prower factor
CF XI
Plasma thromboplastin antecedent
CF XII
Hageman factor
CF XIII
Fibrin-stabilizing factor CF XIII
Damage to cells within blood vessels and outside of the vessels
Tissue factor (aka Tissue Thromboplastin) – released by injured cells, both
injured blood vessel cells and injured tissue cells, activates clotting factors
Tissue factor Proconvertin (CF 7) Stuart-Prower factor (CF 10)
Extrinsic Pathway
Exposure of collagen fibers of subendothelial cells of blood vessels to blood flow
activates clotting factors
This pathway ONLY occurs inside injured blood vessels2
Collagen fibers exposed Hageman factor (CF 12) Plasma thromboplastin
antecedent (CF 11) Christmas factor (CF 9) Stuart-Prower factor (CF 10)
Intrinsic Pathway
Picking up where the extrinsic and intrinsic pathways left off: activation of CF 10
CF 10 Prothromin (CF 2) thrombin fibrinogen (CF 1) fibrin
Fibrin forms a net and traps the formed elements in blood COAGULATION
(blood clot)
clotting cascade
___ is a necessary component of coagulation
Ca2+
Patients with severe blood loss are given _____ ____ injections to help with
blood clotting
calcium chloride
ONLY occurs inside injured blood vessels
Platelet Activation and the Platelet Plug
Platelet Activation and platelet plug release
- exposure of collagen fibers of subendothelial cells of blood vessels to
blood flow - von Willebrand factor (circulating in blood in inactive form) becomes
activated and attaches to the exposed collagen fibers, stopping
movement of platelets platelets form a single layer on top of the
exposed collagen - Platelets become activated and then attach a second layer of platelets,
etc.
Platelet activation results in the formation of a platelet plug
The platelet plug physically (mechanically) blocks the damaged blood vessel
can be formed inside and outside vessels
blood clots
can only be formed inside a blood vessel
platelet plugs
Activated platelets release
ADP – promotes platelet activation
o Thromboxane A2 (TxA2) – vasoconstriction
o Growth factors – promote wound healing, fibroblast chemotaxis
3 components of Anticoagulation system
hemodynamics
endothelial mediation
fibrinolitic sytem
Hemodynamics
– slow blood flow is important for coagulation otherwise
activated CFs get washed out and a clot cannot be formed
Endothelial mediation
platelet plug is formed, surrounding uninjured
endothelial cells release prostacyclin (PGI2) which prevents extra or
excess platelet aggregation
Fibrinolitic system
– CF 12 also activates tissue plasminogen activator,
which converts plasminogen into plasmin, resulting in degradation of
activated CFs
–pinpoint hemorrhages (eg scury)
Petechiae
