Exocrine glands show an excretory duct, which connects the secretory units (in red) with the free surface of the epithelium. The morphology and arrangement of both secretory and excretory parts result in a wide variety of exocrine glands (see table). Compound exocrine glands show branched excretory ducts, branched glands show several secretory units releasing to a single excretory duct, and simple exocrine are not branched at al and has one secretory unit. Regarding the secretory units, exocrine glands are known as tubular (tubuloacinar), acinar, or alveolar, depending on the organization and morphology of the secretory cells. The gland in the image above looks like an acinar branched gland (but not compound), because several secretory units can be seen, but just one unbranched secretory duct.