30 fascinating body facts What does your tongue print look like? What is the hardest substance in the human body? Get these - and many more - answers right here.

The fingernail of a healthy person takes four to six months to grow out completely. Here are some more fascinating body facts.

One in every 1000 babies is born with a tooth.

A person will die from lack of sleep sooner than they will from starvation, which usually takes a few weeks.

Eighty percent of people infected with the Ebola virus, will die from this disease.

Humans have 46 chromosomes, peas have 14 and crayfish have 200.

There are approximately 96,000 km of blood vessels in the human body.

If the lining of mucus were to disappear from your stomach, your stomach would digest itself.

Each person sheds 22 kilograms of skin in his or her lifetime.

More germs are transferred shaking hands than kissing.

Your heart beats 100 000 times a day.

A foetus only acquires fingerprints at the age of three months.

Guys are more likely than girls (by a ratio of 3-to-2) to have bad acne.

We share 98.4% of our DNA with a chimp - and 70% with a slug.

Human foetuses react to loud rock music by kicking.

At just 12 weeks the human foetus can scowl and squint.

If you remove the minerals from a bone by soaking it overnight in a six percent solution of hydrochloric acid, it will become so soft, you could tie it in a knot.

One person in 20 has an extra rib, and they are most often men.

When you were born, you had 300 bones. Now you have 206, if you are an adult. The rest of the bones have not disappeared – they have merely fused together.

The female egg cell is the largest cell in the human body. It is about 175 000 times heavier than the smallest cell, the male sperm cell.

The average person has about 100 000 scalp hairs.

When you look at an object, the image of that object appears upside down on your retina. However, your brain automatically corrects for this, allowing you to perceive the object the right side up.

Enamel, found on our teeth, is the hardest substance in the human body.

Aspirin and alcoholcan be absorbed directly into the bloodstream through the stomach lining.

The soles of your feet contain more sweat glands and more pressure-sensitive nerve endings per square inch than any other part of your body.

Like fingerprints, every person has a unique tongue print.

The kidneys filter your blood up to 300 times per day.

During the first six weeks of life, there is no difference between the male and female embryo.

Human fingers stretch and bend about 25 million times in a normal lifetime.

The human body contains 30 000 billion red blood cells.

Tooth decay has led to 60 percent of adult Americans losing their upper right, middle molar.

Source: The People's Almanac 2, compiled by David Wallechinsky and Irving Wallace.