exocrine gland A gland that secretes products (excluding hormones and other chemical messengers) into ducts (duct glands) which lead directly into the external environment[WP]. Typical exocrine glands include sweat glands, salivary glands, mammary glands, stomach, liver, pancreas AEO:0000097 BTO:0000765 CALOHA:TS-2012 Currently this is logically defined by the system it belongs to, but a better system may be base this on presence/absence of ducts. However, the dual nature of the liver should be taken into consideration here. Consider adding subclasses EHDAA2:0003097 EMAPA:35327 FMA:9596 GAID:34 MA:0002564 MESH:A10.336 UBERON:0002365 UMLS:C0015282 ducted gland glandula exocrina uberon gland