Why only two coronary arteries?
D000818:Animals; D001011:Aorta / Q000033:anatomy & histology; D001158:Arteries / Q000033:anatomy & histology; D003330:Coronary Vessel Anomalies; D003331:Coronary Vessels / Q000033:anatomy & histology*; D003670:Deer / Q000033:anatomy & histology*; D006321:Heart / Q000033:anatomy & histology; D006801:Humans