Term: atrium basal region
Name: atrium
Synonyms:
Definition: Cavitated compound organ that receives inflow of deoxygenated blood and delivers it to a muscular cardiac ventricle. Valves are present to direct flow. There are only two chambers present in the fish heart.
Ontology: Anatomy Ontology [ZFA:0000471]

Name: basal region
Synonyms:
Definition: Anatomical region located basally on the body or body part.
Ontology: Spatial Ontology [BSPO:0000074]