Source:http://linkedlifedata.com/resource/umls/id/C1180083
FMA: Anatomical space which contains portions of one or more body substances and is bounded by the internal surface of one maximally connected anatomical structure or two or more adjacent anatomical structures. Examples: pharyngeal recess space, nasal cavity, cavity of serous sac, lumen of stomach, lumen of artery, fornix of vagina.,UWDA: Anatomical space that is bounded by the surface of the wall or walls of organs, organ parts, body parts or body part subdivisions. Examples: cranial cavity, pharyngeal recess, nasal cavity, tooth socket, cavity of serous sac, lumen of stomach, lumen of artery, fornix of vagina.