anatomical structure

An anatomical structure is a material, physical entity — a single, connected biological object with an inherent three-dimensional shape that is generated by the coordinated expression of an organism's own genome during development. This definition distinguishes anatomical structures from, say, spaces (cavities), processes (physiological events), or external objects. The 'inherent 3D shape' criterion emphasizes that the form arises from developmental programming rather than external forces.

Anatomical structures encompass a broad hierarchy: from macroscopic organs (heart, liver, lung) and organ systems (nervous system, musculoskeletal system), down through tissues (cartilage, bone, epithelium), cells (neurons, hepatocytes), and even subcellular organelles (nucleus, mitochondria). Each level represents a discrete, connected entity with a characteristic shape arising from genomic expression — all qualify as anatomical structures under standard biological ontology definitions.

In formal biological ontologies such as the Foundational Model of Anatomy (FMA) and UBERON, 'anatomical structure' serves as a top-level class that organizes all physical body parts in a hierarchical, machine-readable knowledge representation. These ontologies support biomedical databases, electronic health records, and research data integration by providing standardized, species-neutral terms for body part concepts across taxa.