The Incredible Human Body

1. The Eyes
   

   

   • Each eye has 130,000,000 light receptors which send impulses to the brain
   • Do you know that the human eye is so sensitive that a person sitting on top of a hill on a moonless night could see a match being struck up to 80 km away?
   • We blink our eyes about 20,000 times a day

2. The Skin
   

   

   • The skin has a vast network of receptors. If a hot object touches the skin, some of the 30,000 “hot spots” will warm of the danger. It has 250,000 cold receptors and about 500,000 touch receptors. The brain pays little attention to messages sent by only a few receptors.
   • Most people shed 40 pounds of skin in a lifetime

3. The DNA



A typical DNA molecule is so long and thin that if it were the thickness of spaghetti, it would be 5 miles or 8 km long.

4. The Cells



There are 26 billion cells in a new born baby and about 100 trillion cells in an adult. There are about 210 known distinct human cell types.

5. The Bones



There are 206 bones in the average body. However, there are a few people who have more, such as an extra pair of ribs, making 13 pairs instead of 12 and therefore 208 bones in total.

6. The Organs



At least 21 different organs - such as heart, liver and kidneys - can now be successfully transplanted into patients. Kidneys are the most common organs to be transplanted; they remove waste products from the blood stream.

7. The Fingernails



Nails grow at an average rate of 3 millimeters a month. The slowest growing finger nail is on the thumb nail and the fastest growing is the fingernail on the middle finger.

8. The Muscles



The strongest muscle in the body is the masseter muscle, which is located in the jaw.

9. The Brain



The brain sends messages to other parts of the body at the rate of 240 mph.

10. The Tongue



The tongue has 3,000 taste buds, each with a sensory nerve connected with the brain that carries impulses which the brain interprets and passes judgment.

11. The Ears



The ears have 100,000 auditory cells. Minute nerves ending in the inner ear pick up a particular sound frequency and start vibrating.

12. Hair

    

    We have about 100,000 hairs on our head.

Other interesting things about the human body:

• During a night's sleep a person may change position as many as 40 times and have around 5 dreams
• One in three children in America has a weight problem, and over 9 million are obese or overweight
• Eating lots of eggs, meat, or cauliflower can lead to really stinky farts