Which clotting factors are primarily affected by Heparin?

Heparin primarily affects the anticoagulation cascade by activating antithrombin III, which inhibits thrombin (factor II) and factor Xa. This mechanism is crucial for its role as an anticoagulant in clinical settings.

The correct response highlights that the two primary targets of Heparin are factor II (thrombin) and factor X, which are both critical in the coagulation process. While factor IX is also involved in the coagulation cascade, it is not directly targeted by Heparin's primary mechanism, which focuses on thrombin and factor Xa inhibition.

Factors involved in the coagulation cascade and their interactions with Heparin are essential knowledge for surgical practice and patient management, particularly in preventing thromboembolic events during and after surgical procedures. Thus, understanding that Heparin has a primary impact on factors II and X aligns with the pharmacological principles of anticoagulation therapy.