Source:http://linkedlifedata.com/resource/umls/id/C0929962
FMA: Immaterial anatomical entity which has three spatial dimensions. Examples: celom, thoracic cavity, lesser sac of peritoneum, cavity of right atrium, lumen of aorta, mediastinal space, space of anterior compartment of forearm, intervertebral foramen space.,UWDA: Non-material physical anatomical entity of three dimensions, which is generated by morphogenetic or other physiologic processes; is surrounded by one or more anatomical structures; contains one or more body substances or anatomical structures. Examples: celom, thoracic cavity, lesser sac of peritoneum, cavity of right atrium, lumen of aorta, mediastinum, anterior compartment of forearm, intervertebral foramen.