part of epithelial cell myoepithelium myoepithelial cell BTO:0002309 BrendaTissueOBO Modified smooth muscle cells, contractile in nature, believed to be of ectodermal origin, located around the secretory units of certain glands (salivary, mammary, sweat, and lacrimal glands) between the gland cells and basement membrane, having long dendritic interweaving cytoplasmic processes, and containing myofilaments. It is assumed that contraction of these cells functions to help express secretion from the gland.