Location:
Between left ventricle and aorta; includes noncoronary (posterior semilunar), right coronary (semilunar) and left coronary (semilunar) cusps.

Function:
Opens during systole; blood is ejected from left ventricle into aorta.
Closes during diastole; prevents reflux from aorta into left ventricle.

Importance in cardiovascular diseases:
Aortic stenosis (genetic or acquired), aortic regurgitation.

Importance in device delivery:
Artificial valves - bioprosthetic (xenograft, homograft) and mechanical.

Lambl's Excrescence:
The whisker-like filiform structures, can be seen on some of the aortic valves.