Coagulation factors

Question 1

Factor I (fibrinogen)

Answer 1

Thrombin converts fibrinogen into fibrin, which forms the fibrin blood clots

Question 2

Factor II (Prothrombin)

Answer 2

Prothrombin becomes converted into thrombin which cleaves fibrinogen; thereby, forming fibrin.
- fibrin molecules form fibrin fibers.
- Thrombin also activates: Factor XIII
Factor XIIIa = induces crosslinking of fibrin fibers, thus forming a secure fibrin clot

Question 3

Factor III (tissue factory)

Answer 3

tissue factor is already active in the vasculature subendothelial tissue. It is not exposed to the blood in udamaged bessels

• when injury occurs to the endothelial cells lining the blood vessel, tissue factor is exposed to Factor VII contained in the blood plasma
• tissue factor then binds to Factor VII and activates it into VIIa.
• Tissure factor, Factor VIIa and Ca2+ form a complex that activates Factor X into factor Xa

Question 4

Factor IV (Ca2+

Answer 4

Ca2+ acts as a cofactor with most of the coagulation factors

Question 5

Factor V:

Answer 5

Factor V is released by activated platelets

• becomes activated into Factor Va by thrombin and then forms a complex with Factor Xa and Ca2+ and phospholipids to form the prothrombin activator complex
• This complex rapidly activates prothrombin into thrombin

Question 6

NO FACTOR VI

Answer 6

NO FACTOR VI

Question 7

Factor VII

Answer 7

Factor VII is activated by tissue factor

- Factor VIIa forms a complex with tissue factor and Ca2 wich functions to activate Factor X

Question 8

Factor VIII

Answer 8

thrombin activates factor VIII

• Factor VIIIa complexes with factor IXa and Ca2 and phospholipids to form the tenase complex
• tenase complex rapidly activates Factor X

Question 9

Factor IX

Answer 9

Factor XIa activates Factor IX.

- Factor IXa then forms the tenase complex, which rapidly activates Factor X into Factor Xa

Question 10

Factor X

Answer 10

The Tenase complex activates Factor X

• Factor Xa forms the prothrombin complex with factor Va, Ca2 and phospholipids
• THe PROTHROMBIN COMPLEX rapidly activates PROTHROMBIN INTO THROMBIN

Question 11

Factor XI

Answer 11

Factor XIIa activates Factor XI

Factor XIa then activates Factor IX

Question 12

Factor XII

Answer 12

Factor XII is activated when it is exposed to collagen at sites of injury
- Factor XIIa then activates Factor XI

Question 13

Factor XIII

Answer 13

Factor XIII is activated by thrombin.

- Factor XIIIa acts to crosslink fibrin fibers helping to form a secure fibrin clot