Kalmar “corneum” ana amfani da ita ne a mahallin ilmin halitta kuma tana nufin mafi girman Layer na epidermis, wanda shine mafi girman fata. Musamman, corneum yana kunshe da matattun ƙwayoyin fata da suka mutu da ake kira corneocytes waɗanda wani abu mai suna keratin ke riƙe tare. Corneum yana aiki a matsayin shinge na kariya ga fata, yana taimakawa wajen hana asarar ruwa da kuma kare jiki daga cututtuka na waje da cututtuka.