Blood 9 Flashcards
What is needed to make Fibrin stable?
Factor 13 and calcium
What makes up the network of a blood clot?
Fibrin
What is Fibrin derived from?
Fibrinogen in the presence of Thrombin
What is the Precursor to Thrombin?
Prothrombin in the presence of Prothrombinase
What is unique about Prothrombinase?
It is not a single substance but a complex substance made out of several things
What is Prothrombinase made of?
- Factor X
- Factor V
- Calcium ions
- Phospholipids on the platelet surface
Which parts of prothrombinase are present in an active form?
Factors V and X
How many pathways lead to an active factor X?
Two
What are the names of the two pathways that lead to an active factor X?
Intrinsic and Extrinsic pathway
What is clotting initiated by when you put blood in a test tube?
The glass of the test tube because it is a foreign substance
What pathway of blood clotting is activated by blood meeting the foreign substance of glass in at es tube?
The intrinsic pathway
What is meant by the Intrinsic blood clotting pathway?
Everything needed for the blood to clot is already present in the blood and you don’t need to add anything
What does the Intrinsic Pathway begin with?
Activation of factor XII through contact activation
What is factor XII activated by in the Intrinsic pathway?
Contact activation
What does factor XII activate in the Intrinsic Pathway?
Factor XI
What activates factor XI in the intrinsic pathway?
Factor XII
What does factor XI activate and what does it need to be in the presence of in the intrinsic pathway?
Factor IX in the presence of calcium
What activates factor IX in the intrinsic pathway?
Factor XI in the presence of calcium
What occurs in the intrinsic pathway after factor IX has been activated?
It forms a complex with VIII, calcium and phospholipids from platelets
What is Tenase?
The complex of Factor IX, VIII, calcium and phospholipids from platelets that forms in the intrinsic pathway
What does Tenase do in the Intrinsic pathway?
It activates factor X
When does the Extrinsic pathway of blood vessels occur?
When tissues are damaged inside the living body
What triggers clot formation in the Extrinsic pathway of blood clotting?
TF becoming exposed when a tissue is damaged
What does TF form a complex with in the Extrinsic pathway?
Factor VII, Calcium and the phospholipids from platelets
What happens after TF forms its complex in the extrinsic pathway?
It activates factor X
What does the activated factor X do in the common pathway?
Forms a complex called prothrombinase
What does the Extrinsic pathway require the addition of?
TF which is not usually found in the blood
Which factor deficiencies cause severe bleeding?
VII, VIII
Which clotting factor causes moderate bleeding?
XI
What does the lack of clotting factor XII cause?
No bleeding problem in vivo; failure to clot in vitro
