Depending on recipe and cooking method it may be either a flaky potato pie, or a heavy potato pudding.
Ductus arteriosus: A short vessel through which blood headed from the heart via the pulmonary artery to the lungs is shunted before birth. This blood is shunted away from the lungs and returned to the aorta. When the shunt is open, it is said to be patent.
The ductus arteriosus is open during prenatal life, allowing most of the blood of the fetus to bypass the lungs, but normally this channel closes shortly after birth and changes into a fibrous cord called the ligamentum arteriosum.