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.
If you notice any of the following signs of gum disease, see your dentist immediately: 1  gums that bleed when you brush your teeth. 2  red, swollen or tender gums. 3  gums that have pulled away from the teeth.  bad breath that doesn't go 1  away. pus between your teeth and gums.  loose 1  teeth. a change in the way your teeth fit together when you  bite.