The stomach’s digestive acids are strong enough to dissolve zinc. Fortunately for us, the cells in the stomach lining renew so quickly that the acids don’t have time to dissolve it.
The lungs contain over 300,000 million capillaries (tiny blood vessels). If they were laid end to end, they would stretch 2400 km (1500 miles).
A man’s testicles manufacture 10 million new sperm cells each day – enough that he could repopulate the entire planet in only 6 months!
Human bone is as strong as granite in supporting weight. A block of bone the size of a matchbox can support 9 tones – that is four times as much as concrete can support.
Each finger and toenail takes six months to grow from base to tip.
The largest organ in the body is the skin. In an adult man it covers about 1.9 m2 (20 sq. ft). In a lifetime each person sheds around 18 kg (40 lb) of skin.
When you sleep, you grow by about 8 mm (0.3 in). The next day you shrink back to your former height. The reason is that your cartilage discs are squeezed like sponges by the force of gravity when you stand or sit.
The average person in the west eats 50 tones food and drinks 50,000 liters (11,000 gallons) of liquid during his life.
Each Kidney contains 1 million individual filters. They filter an average of around 1.3 liters (2.2 pints) of liquid during his life.
The focusing muscles of the eyes move around 100,000 times a day. To give your leg muscles the same workout you would need to walk 80 km (50 miles) every day.