Neonatal Nurse Practitioner Practice Exam

Pro-coagulation factors II, VII, IX, and X are activated by which of the following?

1. Fibrinogen maturation

2. Prothrombin

3. Vitamin K

4. Calcium ions

The correct answer is: Vitamin K

The correct answer is Vitamin K because it plays a critical role in the synthesis and activation of several pro-coagulation factors, specifically factors II (prothrombin), VII, IX, and X. These factors are dependent on Vitamin K for their post-translational modifications, which facilitate their function in the coagulation cascade. Without adequate Vitamin K, the carboxylation of specific glutamic acid residues in these factors cannot occur, leading to impaired clotting ability and increased bleeding risk. Factors II, VII, IX, and X are part of the vitamin K-dependent clotting factors. The activation of these factors is essential for effective blood coagulation. Prothrombin, while critical in the coagulation process as it is the precursor to thrombin, is not responsible for the activation process. Fibrinogen maturation does not directly involve the activation of these specific pro-coagulation factors, although fibrinogen is a crucial end-product in the coagulation cascade. Calcium ions do play a role in the coagulation process by facilitating the binding of various factors; however, they are not the ones that activate the aforementioned pro-coagulation factors directly. Therefore, the essential role of Vitamin K in activating factors II, VII, IX