Right auricular appendix

The right auricular appendix (right auricula, right auricle) is a small conical muscular pouch attached to the right atrium of the heart. Its margins present a dentated edge. It projects from the upper and front part of the sinus forward and toward the left side, overlapping the root of the aorta.

The right auricle, along with the right atrial body, is lined with pectinate muscles that form a network of hills and furrows that give it a trabeculated surface.

In older texts, the term "right auricle" was often used to describe the structure now known as the right atrium.