Organ
Auricles (atrial appendages)
Atrial appendages beside the great-vessel roots
High-yield
The left appendage is an important site of clot formation when atrial fibrillation causes ineffective contraction and stasis. The two appendages differ substantially in shape and internal architecture.
Overview
Each atrium has a muscular appendage, or auricle, with a ridged internal surface. The broad right appendage lies beside the ascending aorta; the narrower left appendage lies near the pulmonary trunk and left atrioventricular groove.
Reference facts
- Location
- Right appendage beside the ascending aorta; left appendage near the pulmonary trunk and left atrioventricular groove
- Parts
- Pectinate-lined outpouchings that communicate with their respective atria; shape and openings vary
- Blood supply
- Atrial branches of the right coronary artery on the right and chiefly circumflex branches on the left
- Innervation
- Autonomic fibers from cardiac plexuses and nearby intrinsic neural networks
- Relations
- The left appendage is close to the circumflex artery and great cardiac vein; the right is close to the aortic root
- Function
- Contribute to atrial volume handling and contraction; appendage tissue also releases natriuretic peptides
Clinical correlation
Clots formed in the left appendage can embolize into the systemic circulation. Its wall and neighboring coronary structures require careful assessment during procedures involving this region.
Frequently asked questions
Where are the auricles (atrial appendages) located?
Right appendage beside the ascending aorta; left appendage near the pulmonary trunk and left atrioventricular groove.
What do the auricles (atrial appendages) do?
Contribute to atrial volume handling and contraction; appendage tissue also releases natriuretic peptides.
What are the parts of the auricles (atrial appendages)?
Pectinate-lined outpouchings that communicate with their respective atria; shape and openings vary.
What is the blood supply of the auricles (atrial appendages)?
The auricles (atrial appendages) are supplied by the atrial branches of the right coronary artery on the right and chiefly circumflex branches on the left.