An anticoagulant present in blood which prevent activation of prothrombin -

The correct answer is Heparin.

Key Points

• Heparin is a naturally occurring anticoagulant found in the blood that prevents blood clotting by inhibiting the activation of prothrombin.
• It works by enhancing the activity of antithrombin III, which inactivates thrombin and prevents the conversion of fibrinogen to fibrin.
• Heparin is commonly used in medical settings to prevent clot formation during surgeries or in patients with risk factors for blood clots.
• Heparin does not dissolve existing clots but prevents the formation of new clots, thus inhibiting the clotting cascade.

Additional Information

• Prothrombin Activation:
  • Prothrombin is a precursor to thrombin, which plays a crucial role in the conversion of fibrinogen to fibrin during blood clotting.
  • Heparin prevents the activation of prothrombin by inhibiting thrombin's activity, thereby controlling blood clotting.
• Anticoagulants:
  • Anticoagulants like heparin are crucial in managing conditions such as deep vein thrombosis, pulmonary embolism, and atrial fibrillation.
  • Other examples of anticoagulants include warfarin and direct oral anticoagulants (DOACs) that target different stages of the coagulation process.
• Heparin vs. Other Anticoagulants:
  • Unlike warfarin, which acts on vitamin K-dependent clotting factors, heparin works by enhancing antithrombin III and directly inhibiting thrombin.
  • Heparin is fast-acting and typically administered through injection, whereas warfarin is taken orally and requires regular monitoring of blood clotting levels.
• Medical Uses of Heparin:
  • Heparin is used to prevent clotting during surgeries, dialysis, and in patients who require long-term immobilization.
  • It is also used in emergency settings to manage acute conditions such as heart attacks and strokes.