The secretory cell is released and as it breaks apart, the contents of the cell become the secretory product. This mode of secretion results in the most complex secretory product. Some sweat glands located in the axillae, pubic areas, and around the areoli of the breasts release their products in this manner. Sebaceous glands also are of this type. Regardless of gland type, structural complexity, or mode of secretion, epithelia are the secretory cells of all glands .
Epithelia also form the ducts that connect the glands to the surface.
When ducts are present and cut in longitudinal or cross-section, epithelial cells are also seen making up these structures. Simple cuboidal epithelia are the most typical type found in the body and ducts of exocrine glands. Endocrine Glands Endocrine glands are the hormone producing structures of the body. Some, like the thyroid are large and obvious. Others, for instance the islet cells of the pancreas, are small islands of endocrine cells embedded within the larger exocrine portion of this organ.