1. 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.
2. The lungs contain over 300,000 million capillaries (tiny blood vessels). If they were laid end to end, they would stretch 2400km (1500 miles).
3. A mans testicles manufacture 10 million new sperm cells each day – enough that he could repopulate the entire planet in only 6 months!
4. 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.
5. Each finger and toenail takes six months to grow from base to tip.
Sources: Reader’s Digest Book of Facts
2. The lungs contain over 300,000 million capillaries (tiny blood vessels). If they were laid end to end, they would stretch 2400km (1500 miles).
3. A mans testicles manufacture 10 million new sperm cells each day – enough that he could repopulate the entire planet in only 6 months!
4. 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.
5. Each finger and toenail takes six months to grow from base to tip.
Sources: Reader’s Digest Book of Facts