The human brain contains about 100 000 million nerve cells, each of which is connected to many others—perhaps as many as 50 000 others. The brain is the organ of our thinking and of our memory. It integrates information from the outside world and so allows us to perceive objects and events around us. It [...]
Hepatitis B, the type of viral hepatitis that is conveyed from person to person in “biological fluids,” is a potential risk of transfusions when the blood obtained from an unknown donor who might be a hepatitis carrier. Normally, we would not expect to become infected with this virus merely by touching surfaces that have been [...]
Signs and symptoms The key sign of a hernia is a bulge in one of the typical locations: just above the crease of the groin; in the scrotum of a boy; in the labia majora of a girl; below the crease of the groin; just above or below the navel; or at the navel. A [...]