sebaceous gland, one of the many small sacculated organs in the dermis. They are located throughout the body in close association with all types of body hair but are especially abundant in the scalp, face, anus, nose, mouth, and external ear. They are rare in the palms of the hands and the soles of the feet. Each gland consists of a single duct that emerges from a cluster of oval alveoli. The ducts from most sebaceous glands open into the hair follicles, but some open onto the skin surface, as in the labia minora and the free margin of the lips. The sebum secreted by the glands oils the hair and the surrounding skin, helps prevent evaporation of sweat, and aids in the retention of body heat. The sebaceous glands in the nose and face are large and lobulated and often swell with accumulated secretion. Compare sudoriferous gland.
