Atrii - Auricula

: A bloused fold projecting from the left atrium that lies near the left pulmonary veins. Functional Significance

: They act as "reservoirs" that can expand to increase the capacity of the atria during periods of high cardiac output or when blood flows quickly back to the heart. auricula atrii

: A wedge-shaped or conical pouch located at the front upper surface of the right atrium . It overlaps the root of the aorta. : A bloused fold projecting from the left

: The right atrial appendage (RAA) specifically helps manage blood volume by releasing certain proteins. Clinical Importance It overlaps the root of the aorta

: These appendages have a rough, trabeculated inner surface due to a network of pectinate muscles , which distinguishes them from the smoother main bodies of the atria. Location :

The auricles are significant in clinical medicine because their "pouch-like" nature can allow blood to pool or become stagnant if heart beats are irregular (such as in atrial fibrillation). This stagnation can lead to the formation of blood clots, particularly in the left atrial appendage (LAA), which may then travel to other parts of the body.