Sebaceous gland Sebaceous gland Sebaceous glands are microscopic exocrine glands in the skin that secrete an oily or waxy matter, called sebum, to lubricate and waterproof the skin and hair of mammals. In humans, they occur in the greatest number on the face and scalp, but also on all parts of the skin except the palms of the hands and soles of the feet. The type of secretion of the sebaceous glands is referred to as holocrine. In the eyelids, meibomian glands, also called tarsal glands, are a type of sebaceous gland that secrete a special type of sebum into tears. Fordyce
Meibomian gland eye conditions. They may also contribute to blepharitis. The glands are named after Heinrich Meibom (1638–1700), a German physician. Lipids are the major components of meibum (also known as "meibomian gland secretions"). The term "meibum" was originally introduced by Nicolaides "et al." in 1981. The biochemical composition of meibum is extremely complex and very different from that of sebum. Lipids are universally recognized as major components of human and animal meibum. Recently, an update on the composition of human meibum and on the structures of various positively identified meibomian lipids was published. Currently, the most sensitive and informative approach to