Within a tiny droplet of blood, there are some 5 million red blood cells. Every second, 5 people are born and 2 people die- a net gain of 3/second. Each human hair on the scalp has a life span of about three years. A camel can lose up to 30 percent of its body's water in perspiration and continue to cross the desert. A human would die of dehydration after losing only 12 percent of body's water. Like a finger print, every person has a unique tongue print. The heart is the strongest muscle in the body. It pumps the blood throughout the body for the entire lifetime.