... lining the cavities and ducts of the body and all body sur-faces. The epithelium forms the skin, the lining of the GASTROINTESTINAL TRACT and ducts of secretorytissues like the LIVER and PANCREAS, ... mammary glands,digestive glands like salivary glands, and the pan-creas. Endocrine epithelium secretes hormonesinto blood. Examples are the pituitary gland, thy-roid gland, ADRENAL GLANDS, ... endocrinegland until birth. During pregnancy the placentasecretes chorionic gonadotropin, a hormone capa-ble of stimulating the growth and function of the gonads, as well as estrogen and progesterone....