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.
Bite tightly on the gauze. After a tooth extraction, your dentist will place a gauze on the wound to stop the bleeding. Make sure to bite down tightly on the gauze to apply pressure to the area to stop bleeding. If heavy bleeding continues, you may need to reposition the gauze pack to cover the wound more directly. If you feel unusual pain after a week of extraction, visit your dentist. 2  Light bleeding and discolored saliva will be present during the first 12 to 24 hours. 3  If heavy bleeding has not stopped 3-4 hours after the procedure, visit your dentist immediately.