Term: hemal arch anatomical region
Name: hemal arch
Synonyms: haemal arch, ventral arcocentrum
Definition: Hemal arches extend ventrally from the centra of caudal and transitional vertebrae to enclose the caudal artery and vein. In cyprinids, the hemal arch forms directly in membrane bone.
Ontology: Anatomy Ontology [ZFA:0000519]

Name: anatomical region
Synonyms:
Definition: A 3D region in space without well-defined compartmental boundaries; for example, the dorsal region of an ectoderm.
Ontology: Spatial Ontology [BSPO:0000070]