Basic Facts About Human Beings

• 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 2400km (1500 miles).
•  A mans 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 tonnes – that is four times as much as concrete can support.
•  Each finger and toenail takes six months to grow from base to tip.
•  The average person in the West eats 50 tonnes of 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 blood per minute, and expel up to 1.4 liters (2.5 pints) a day of urine.
•  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 80km (50 miles) every day.
•  In 30 minutes, the average body gives off enough heat (combined) to bring a half gallon of water to boil.
•  A single human blood cell takes only 60 seconds to make a complete circuit of the body.