Activation of factors XII (Hageman) and XI (PTA) by skin contact.
D001777:Blood Coagulation; D001779:Blood Coagulation Factors; D005172:Factor XI; D005174:Factor XII; D066298:In Vitro Techniques; D012867:Skin
D001779:Blood Coagulation Factors; D005174:Factor XII; D005172:Factor XI