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Unified Medical Language System® (UMLS®)

Foundational Model of Anatomy Source Information

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The Structural Informatics Group (SIG) at the University of Washington developed and maintains the Foundational Model of Anatomy ontology (FMA). The FMA project is an information resource integrated in SIG's Anatomy Information System. 

FMA is open-source and available for general use.

FMA is a reference ontology for the domain of anatomy and makes available anatomical information in symbolic form. Its intent is to encode anatomical knowledge that can be reused for any application to serve the needs of any user group.

FMA is designed to provide anatomical information needed by any user group and is intended to accommodate any viewpoint. The ontology encodes anatomical knowledge in a way that can support machine-based inference. 

FMA consists of 75,000 anatomical classes; 130,000 unique terms; over 205,000 frames; and 174 unique slots in use representing different types of relations, attributes and attributed relationships. There are over 44,000 English synonyms, of a class's preferred name, as well as more than 15,000 non-English equivalents. The relationship network of the FMA contains more than 2.5 million relationship occurrences. Over 1,000,000 of these occur on classes, about 450,000 of which relate classes directly to other classes. The FMA contains 8,500 Latin; 4,700 French; 500 Spanish; and 350 German terms.

The Metathesaurus representation of FMA includes only English and Latin strings.

FMA is a biomedical informatics resource for knowledge modelers and developers, and facilitates the development of anatomy content for applications that target specific user groups.

Sites Consulted

  1. Foundational Model of Anatomy ontology [Internet]. Seattle (WA): Structural Informatics Group. About FMA; [cited 2008 Sep 17]. Available from:
  2. Foundational Model of Anatomy ontology [Internet]. Seattle (WA): Structural Informatics Group. FAQs; [cited 2008 Sep 17]. Available from: