6.) Identify the unique structures of the left atrium.
The left atrium receives the pulmonary veins from the lungs.
Auricle (appendage): muscular pouch that is located in the superior, left border (often overlapping the root of the pulmonary trunk)
- Internally, has pectinate muscles
- Only area of the internal L. atrium with pectinate muscle (the rest is mostly smooth-walled)
L. atrioventricular (mitral) valve orifice
- The L. AV valve is located between the L. atrium and L. ventricle
- Wall between the R. and L. atrium
Semilunar depression: a small depression in the interatrial septum that represents the floor of the fossa ovalis