ANATOMY

Detailed explanation-1: -The moderator band (MB, also known as the septomarginal trabecula) found in all human hearts is derived from the muscle band of the interventricular septum, begins below the septal end of the supraventricular crest, and runs toward the anterolateral wall of the ventricle [1].

Detailed explanation-2: -They arise from the inner walls of the left and right ventricle and attach to mitral and tricuspid valve leaflets respectively via chordae tendinae. Historical documentation of the existence of papillary muscles as a component of cardiac anatomy exists at least as early as the 16th century.

Detailed explanation-3: -The right atrium has a smooth thin-walled posterior part, called the sinus venarum, where both superior and inferior venae cavae, as well as the coronary sinus open. Then there’s a rough muscular anterior part formed by the pectinate muscles.

Detailed explanation-4: -Its main function is to convey the right branch of the atrioventricular bundle of the conducting system. The septomarginal trabecula forms the anteroinferior border between the superior, smooth outflow tract of the ventricle and the trabeculated inflow tract.

Detailed explanation-5: -Blood supply typically originates from septal perforating branches of the left anterior descending artery (LAD) which may subsequently anastomose with vessels derived from the right coronary circulation.