Human Body - 2

• You’ll drink about 75,000 litres (20,000 gallons) of water in your lifetime.
• After a certain period of growth, hair becomes dormant. That means that it is attached to the hair follicle until replaced by new hair.
• Hair on the head grows for between two and six years before being replaced. In the case of baldness, the dormant hair was not replaced with new hair.
• Men loose about 40 hairs a day. Women loose about 70 hairs a day.
• In the Middle Ages the length from the tip of the middle finger to the elbow was called an ell.
• A person remains conscious for eight seconds after being decapitated.
• The first successful human sex change took place in 1950 when Danish doctor Christian Hamburger operated on New Yorker George Jorgensen, who became Christine Jorgensen.
• The muscle that lets your eye blink is the fastest muscle in your body. It allows you to blink 5 times a second.
• On average, you blink 15 000 times a day. Women blink twice as much as men.
• A typical athlete’s heart churns out 25 to 30 litres (up to 8 gallons) of blood per minute.
• 24 of the known 118 elements are found in your body – see What the average human body contains
• We have four basic tastes plus umami. The salt and sweet taste buds are at the tip of the tongue, bitter at the base, and sour along the sides; umami is a mixture of tastes sensed along the center of the tongue.
• Not all our taste buds are on our tongue; about 10% are on the palette and the cheeks.
• Unless food is mixed with saliva you cannot taste it.
• The liver is the largest of the body’s internal organs. The skin is the body’s largest organ.
• On average a hiccup lasts 5 minutes.
• Fingernails grow nearly 4 times faster than toenails.
• Your middle fingernail grows the fastest.
• Your finger nails grow at 1 nanometre per second (0.000 000 001 m/s). Your hair grows at 4 nanometres per second (0.000 000 004 m/s).
• It takes about 3 months for the transplanted hair to start growing again.
• About 13% of people are left-handed. Up from 11% in the past.
• In 1900, a person could expect to live to be 47. Today, the average life expectancy for men and women in developed countries is longer than 70 years.
• A newborn baby’s head accounts for one-quarter of its weight.
• King Henry I, who ruled in the England in the 12th century, standardized the yard as the distance from the thumb of his outstretched arm to his nose.
• The bones in your body are not white – they range in color from beige to light brown. The bones you see in museums are white because they have been boiled and cleaned.
• Our eyes are always the same size from birth.
• Every person has a unique tongue print.
• If all your DNA is stretched out, it would reach to the moon 6,000 times.
• Approximately two-thirds of a person’s body weight is water. Blood is 92% water. The brain is 75% water and muscles are 75% water.
• The colored part of the eye is called the iris. Behind the iris is the soft, rubbery lens which focuses the light on to a layer, called the retina, in the back of the eye. The retina contains about 125 million rods and 7 million cones. The rods pick up shades of gray and help us see in dim light. The cones work best in bright light to pick up colors.
• We actually do not see with our eyes – we see with our brains. The eyes basically are the cameras of the brain.
• Our eyes can detect sound.