The chambers of the heart, to which the BLOOD returns from the circulation.
Heart Atrium,Left Atrium,Right Atrium,Atria, Heart,Atrium, Heart,Atrium, Left,Atrium, Right
D006329
Heart Conduction System
An impulse-conducting system composed of modified cardiac muscle, having the power of spontaneous rhythmicity and conduction more highly developed than the rest of the heart.