Question

Name the thin walled sac lying behind the atria?​

Answer 1

Answer:

Auricles are relatively thin-walled structures that can fill with blood and empty into the atria or upper chambers of the heart.

Answer 2

Explanation:

Surface Features of the Heart

Surface Features of the HeartAuricles are relatively thin-walled structures that can fill with blood and empty into the atria or upper chambers of the heart. ... Major coronary blood vessels are located in these sulci. The deep coronary sulcus is located between the atria and ventricles.