The fine structure of the sinus node in the rat.
D000818:Animals; D001158:Arteries / Q000166:cytology; D001369:Axons; D006329:Heart Conduction System; D009206:Myocardium / Q000166:cytology; D009210:Myofibrils; D051381:Rats; D012849:Sinoatrial Node / Q000098:blood supply / Q000166:cytology*