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.
What Is Periodontal Disease? If your hands bled when you washed them, you would be concerned. Yet, many people think it's normal if their gums bleed when they brush or floss. In a 1999 study, researchers at the U.S. National Institutes of Health (NIH) found that half of Americans over 30 had bleeding gums. Swollen and bleeding gums are early signs that your gums are infected with bacteria.