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.
Bleeding gums is symptomatic of a periodontal gum condition called gingivitis. Flossing the in between area of the teeth removes bacterial plaque which causes the tissue irritation and the bleeding. Keep flossing and the bleeding should stop over a period of a week or so. If it does not there may be a hard deposit called calculus or commonly called tartar present that simple flossing cannot remove.