Tarsus (eyelids) is a groove in the inner surface of each eyelid. Along the inner margin of the tarsus are modified sebaceous glands known as tarsal glands (or meibomian glands), aligned vertically within the tarsi: 30 to 40 glands in the upper lid, and 20 to 30 in the lower lid, which secrete a lipid-rich product which helps keep the lacrimal secretions or tears from evaporating too quickly, thus keeping the eye moist. Tarsus (eyelids) The tarsi (tarsal plates) are two comparatively thick, elongated plates of dense connective tissue, about in length; one is found in each eyelid, and contributes to its
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