Facts About Your Body, Part 5

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, standardised 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 colour 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 grey 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.