Word parts
thromb/o clot-in substance
What it means
A key clotting enzyme. The liver makes its inactive form, prothrombin, with the help of vitamin K. When a vessel is injured, prothrombin is turned into thrombin, which changes fibrinogen into fibrin and helps activate platelets. Heparin works by helping antithrombin block it, and some anticoagulants block it directly. In surgery, topical thrombin is applied to stop oozing blood.
Related terms
anticoagulant
A drug that slows the blood's ability to form clots.
heparin
An anticoagulant drug, given by injection or IV, that keeps blood clots from forming or growing.
thromb/o
A word part that means blood clot.
prothrombin time
A blood test that measures how many seconds it takes a blood sample to form a clot.