attaches_to constitutional_part_of regional_part_of Wall of right side of heart Wall of biatrial part of heart Myocardium of atrium Myocardium of right atrium FMA:83531 Myocardium of atrium which consists of the myocardium proper and the conducting system of the the right atrium that is continuous with the tunica media of superior and inferior vena cavae. Right atrial myocardium fma Myocardium of biatrial part of heart Wall of right atrium Epicardium of right atrium