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.
Occasional bleeding of the gums can be the result of brushing your teeth too vigorously or wearing dentures that donât fit correctly. Frequent episodes of gum bleeding, however, can indicate more serious conditions, such as: 1  periodontitis (an advanced form of gum disease)  leukemia (cancer of the blood)