Aortic valve donation (image 2 of 3). Gloved hands of a surgeon holding an aortic valve that has been removed from a donated human heart. The aortic valve lies between the left ventricle (main pump- ing chamber) of the heart and the aorta, the body's largest artery. Its function is to allow blood to flow out of the chamber but to prevent backwash. The valve can be donated & transplanted into patients whose valve is malfunctioning due to disease. (See photo number M560/245 for a picture of the aortic valve being removed, and M560/247 for the valve packaged for storage.)