One of the heart chambers.
hog:0000328
right atriumhog:0000369
left atriumhog:0000385
interatrial septumhog:0000602
atrium myocardiumhog:0000606
atrium endocardiumhog:0000941
atrium cardiac jellyhog:0001472
atrioventricular valveBFO:0000050
part of
hog:0000276
tao:0000471