The ductus arteriosus is a hole that allows the blood to skip the circulation to the lungs. However, when the baby is born, the blood must receive oxygen in the lungs and this hole is supposed to close. If the ductus arteriosus is still open (or patent) the blood may skip this necessary step of circulation. The open hole is called the patent ductus arteriosus.
Caring for a Bleeding Tooth. Some people mistakenly think that while brushing, a bleeding tooth is perfectly normal. It is not. Anytime there is any bleeding in the mouth, it is almost always a sign of periodontal disease. Even if you brush fairly hard, it should not cause healthy teeth and gums to bleed.
Your bleeding gums when you brush your teeth may be a sign of gum disease or a sign of something more global like a bleeding disorder. In most people, bleeding gums happen when we brush too hard. This does not seem to be the case since you have had similar problems with different tooth brushes. You may have gum disease such as gingivitis (also known as inflammation of the gums). Another possibility is that you have a problem with your blood clotting.