Definition: in the clotting of blood, also known as plasma thromboplastin antecedent, a component of the contact system that is absorbed from plasma and serum by glass and similar surfaces. Its active form, factor XIa (EC 18.104.22.168), is a serine proteinase converting factor IX to factor IXa. Deficiency of factor XI results in a hemorrhagic tendency; is caused by an autosomal recessive gene.
Synonym(s): plasma thromboplastin antecedent
Search Stedman's Medical Dictionary
Examples: glitazone, GI cocktail, etc.