http://hl7.org/fhir/StructureDefinition/bodySite|4.0.1

Record details about the anatomical location of a specimen or body part. This resource may be used when a coded concept does not provide the necessary detail needed for the use case.
element_idtypes
Extension
Extension.extension
Extension.url
Extension.value[x]
Extension
Extension.id
Extension.extension
Extension.url
Extension.value[x]