Anatomical photograph of heart in sheep at one month showing: (AP) apex of heart, (BA) base of heart, (A) right atrium, (B) left atrium, (RV) right ventricle, (LV) left ventricle, (C) cranial border, (D) caudal border, (E) aorta, (red arrow) coronary groove, (yellow arrow) cranial vena cava, (blue arrow) caudal vena cava.