Coagulation

Coagulation is "the process of the interaction of blood coagulation factors that results in an insoluble fibrin clot."

Biochemistry

The Vitamin K dependent coagulation factors are II, VII, IX, and X.

Intrinsic pathway

The intrinsic pathway uses Factors VIII, IX, XI, and XII. The partial thromboplastin time measures the function of the intrinsic pathway and the common pathway.

Extrinsic pathway

The extrinsic pathway uses Factors VII and X. The prothrombin time measures the function of the extrinsic pathway and the common pathway.

Final common pathway

The final common pathway used factors II (prothrombin) and I (fibrinogen).

Disorders of coagulation

Blood coagulation disorders are "hemorrhagic and thrombotic disorders that occur as a consequence of abnormalities in blood coagulation due to a variety of factors such as coagulation protein disorders; blood platelet disorders; blood protein disorders or nutritional conditions."

Factor I deficiency

Deficiency of Factor I (fibrinogen) may be inherited (afibrinogenemia) or acquired.

Factor II deficiency

Deficiency of Factor II (prothrombin) leads to hypoprothrombinemia. The defiency may be acquired in due to prothrombin antibodies.

Factor V deficiency

Factor V deficiency is a "(known as proaccelerin or accelerator globulin or labile factor) leading to a rare hemorrhagic tendency known as Owren's disease or parahemophilia. It varies greatly in severity. Factor V deficiency is an autosomal recessive trait."

Factor X deficiency

Factor X deficiency is a "blood coagulation disorder usually inherited as an autosomal recessive trait, though it can be acquired. It is characterized by defective activity in both the intrinsic and extrinsic pathways, impaired thromboplastin time, and impaired prothrombin consumption."