Extracoronary blood supply of the sinu-atrial (Keith-Flack's) node.
D000790:Angiocardiography; D001161:Arteriosclerosis; D001981:Bronchial Arteries; D006329:Heart Conduction System / Q000098:blood supply*; D006801:Humans; D008171:Lung Diseases; D010784:Photomicrography; D012849:Sinoatrial Node / Q000098:blood supply