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
Submucosal glands sacs (acini) where the mucus originates. Each sac (acinus) has one end that can open and close (dilate) to allow the mucus out. The acini empty into little tubes (tubules) that lead to a reservoir (collecting duct) that has a portal through the "skin" (mucosa) that can open and close allowing the mucus into the main tube. The submucosal glands are a companion to goblet cells which also produce mucus, and are found lining the same tubes. Submucosal glands Submucosal glands can refer to various racemose exocrine glands of the mucous type. These glands secrete mucus to facilitate the movement