Tuesday, 1 April 2008

Top 10 Useless Body Parts

According to the Science Channel we have at least 10 useless body parts. Am sure we have our own ideas as what to add to the list.


10. Plica semilunaris
You may not know it, but you have a third eyelid. Pull open the two more noticeable eyelids and take a look -- it's located right in the corner by the tear duct. This small third eyelid is left over from what's known as a "nictitating membrane," which is still present in full form in some animals including chickens, lizards and sharks.

9. Body hair
No doubt we were once hairier. Up until about 3 million years ago, we were covered with body hair. But by the time Homo erectus arrived, the ability to sweat meant we could shed our woolly ways.

8. Sinuses
Doctors don't really know much about sinuses -- only that we have a lot of them. Possibilities for their function range from insulating our eyes to changing the pitch and tone of our voice.

7. Adenoids
Adenoids trap bacteria, but they're also prone to swelling and infection. Just ask any 7-year-old. Luckily, our adenoids shrink with age and are often removed, along with ...

6. Tonsils
Also prone to swelling and infection. If you still have them when you reach your 30s, it's almost an accomplishment.

5. Coccyx
More useful as a game-winning Scrabble word than as part of the anatomy, the coccyx or tailbone, is made up of several fused vertebrae left over from the olden days when we had tails.

4. Arrector pili
When we were hairier (see No. 9), the arrector pili made the hairs stand on end when we needed to appear bigger and scarier. Now, it just gives us goose bumps.

3. Wisdom teeth
Back in the day, when we ate mammoth meat off the bone and didn't floss afterward, our teeth tended to fall out. Therefore, when those reserve molars, aka "wisdom teeth," came in, they were welcomed. Nowadays, fluoride and dental plans have made them just a huge pain.

2. Appendix
Darwin claimed the appendix was useful for digestion during our early plant-eating years; it's dwindled down to little since we started eating more digestible foods.

1. Male nipples
Because, why?

3 comments:

Semaj Mahgih said...

Well, I needed to know that jsut as I was having my breakfast. Male nipples indeed! :)

LordSomber said...

Male nipples, hah! The reason is simple actually: the nipples develop on a foetus *before* the gender is determined.

Liz said...

I thought our ancestors didn't lose their teeth because they didn't eat so much sugar? Interesting.

I could do with a little less body hair!