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 Stress can cause a reaction from bacteria inside of your mouth that make your gums bleed. Blood happens to tastes like metal, and can be tasted even if the amount of blood is barely perceptible. It's possible that during anxiety attacks and stress, you're experiencing a minor gum bleed.