AnatomicalEntity

An anatomical entity is a distinct structure within a living organism that can be identified by its morphology, spatial relationships, or physiological function. The term is used broadly across biology, from the cellular level, where it may refer to organelles, to the macroscopic level, where it denotes entire organs or organ systems. In a typical definition, an anatomical entity has a well-defined shape, composition, and position, and can be distinguished from other entities by structural or functional characteristics.

In biomedical informatics, anatomical entities form the backbone of many ontologies, most notably the Foundational Model of Anatomy (FMA), the Uberon multi-species anatomy ontology, and the anatomy branches of the Gene Ontology. These formal representations enable consistent annotation of genes, proteins, and diseases across species, supporting tasks such as gene expression mapping, phenotype comparison, and the integration of heterogeneous data sets. Ontological classes capture hierarchical relationships such as part–whole (e.g., a ligament is part of a joint) and developmental lineage (e.g., a heart is derived from the mesoderm).

Researchers and clinicians rely on precise definitions of anatomical entities to describe findings in pathology reports, to plan surgical interventions, and to communicate conditions using standardized vocabularies like SNOMED CT and ICD. By providing a shared reference, these vocabularies reduce ambiguity and improve interoperability among electronic health records, research databases, and knowledge bases.