Coagulation 2 Flashcards
What is the function of actin in the platelet?
helps the platelet contract to form a platelet plug
What is the function of ADP in the platelet?
platelet activation and aggregation
What is the function of serotonin the platelet?
activates nearby platelets
What is the function of glycoproteins?
adheres to injured endothelium, collagen, and fibrinogen
What is the function of growth factor in the platelet?
helps repair damaged vessel walls
Which substance is responsible for adhering the platelet to the damaged vessel?
a. thromboxane A2
b. ADP
c. Tissue factor
d. Von Willebrand factor
d. Von Willebrand factor
Immediately following vascular injury, the vessel (tunica media)
contracts to reduce blood flow to the affected area
Formation of the platelet plug is called
primary hemostasis
Primary hemostasis can be divided into three steps:
adhesion
activation
aggregation
Adhesion is when
after vascular injury, platelets immediately adhere to exposed collagen with the help of von Willebrand factor
Activation is when
platelets contract & release a series of compounds that attract other platelets to the site of injury and promote clotting
Aggregation is when
a platelet plug forms (small injuries)
For larger injuries, the coagulation process is
required to strengthen the clot
What are the four steps in the hemostatic mechanism?
vascular spasm
formation of the platelet plug
formation of the fibrin clot
fibrinolysis
What are the two functions that vascular spasm serves?
reduces blood loss
helps procoagulants remain in the affected area so that they can do their jobs
_____________ links activated platelets together to form the platelet plug
GpIIb/IIIa receptor complex
How does the injured blood vessel initially activate the platelet plug?
endothelial injury exposes collagen. Exposed collagen at the site of vascular injury activates platelets
Match each coagulation factor with its pathway:
calcium, tissue factor, prothrombin, hageman factor
affects all pathways, extrinsic pathway, intrinsic pathway, final common pathway
calcium- affects all pathways
tissue factor- extrinsic pathway
prothrombin- final common pathway
Hageman factor- intrinsic pathway
The classical model of coagulation consists of
two distinct pathways: extrinsic and intrinsic that come together in the final pathway
The _____________ is activated when coagulation is initiated outside of the intravascular space.
Extrinsic pathway
The ______________ is activated when coagulation is initiated inside of the itnravscular space.
Intrinsic pathway
_____________ is a more modern approach to coagulation.
The cell-based model of coagulation
In the cell-based model of coagulation, coagulation is initiated by the ___________________, as injured endothelium releases _________—
extrinsic pathway; tissue factor (factor 3)
In the cell based model of coagulation, the intrinsic pathway serves to
amplify the thrombin generating effect of the extrinsic pathway
__________ coagulation factors participate in the coagulation cascade
12
Explain the numbering of the coagulation factors.
there’s no factor 6, which explains why they’re numbered from 1-13
The primary purpose of the coagulation cascade is to produce
fibrin
What is the mnemonic for remembering the names of the factors?
Foolish people try climbing long slopes after Christmas, some people have fallen
Factor 1 is
fibrinogen
Factor 2 is
prothrombin
factor 3 is
tissue factor
Factor 4 is
calcium ions
Factor 5 is
labile factor
Factor 7 is
stable factor
factor 8 is
antihemophilic factor
Factor 9 is
Christmas factor
factor 10 is
Stuart-Prower factor
Factor 11 is
plasma thromboplastin antecedent
Factor 12 is
Hageman factor
factor 13 is
Fibrin stabilizing factor
All of the factors are synthesized by the __________ except for factors
liver; 3 & 4
Factor 4, calcium ions, are synthesized from the
diet
Factor 3, tissue factor, is synthesized from the
vascular wall
Describe the 6 steps to draw the coagulation cascade:
- count backward from 12
- 3, 4, & 6 don’t exist
- 10 is the frontman in the band- it’s the only one out of order
- 5 & 8 are co-factors so they go above the line
- 7 is lucky, so it goes in your pocket (below the line)
- 2 is prothrombin & 1 is fibrinogen
Vitamin K factors include
2, 7, 9 & 10
The INtrinsic pathway is longer, so it’s measured by the
PTT (more letters)
The EXtrinsic pathway is shorter so it’s measured by the
PT 9fewer letters)
The EXtrinsic pathway looks like a gun, and guns are used in war. therefore, ________ inhibits the extrinsic pathway
WARfarin
The gun of the EXtrinsic pathway is fired with your _________
trigger finger (TF= Tissue factor)
The Extrinsic pathway is activated by
TISSUE Factor
For the final common pathway, just think of dollar denominations:
10, 5, 2 & 1
