vernix caseosa /vur″niks kas′ē·ō″sə/ [Gk, resin; L, caseus, cheese] , a grayish-white cheeselike substance, consisting of sebaceous gland secretions, lanugo, and desquamated epithelial cells, that covers the skin of the fetus and newborn. It acts as a protective agent during intrauterine life and is thought to have an insulating effect against heat loss.
