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This fun article by Christina Laun at BootStrapper explains 100 weird, wacky, and interesting facts about the human body. Here are a few of my favorites:
1. The largest cell in the human body is the female egg and the smallest is the male sperm.
2.The brain is much more active at night than during the day.
3.During your lifetime, you will produce enough saliva to fill two swimming pools.
4.Your nose can remember 50,000 different scents.
5. Women's hearts beat faster than men's.
6. Your eyes are always the same size from birth (but your nose and ears never stop growing).
7. On any given day, sexual intercourse takes place 120 million times on earth.
8. The brain itself cannot feel pain.
9. The largest internal organ is the small intestine.
10. Sneezes regularly exceed 100 mph & nerve impulses to and from the brain travel as fast as 170 miles per hour.
11. It takes 17 muscles to smile and 43 to frown.
Check out the rest of the article for more.
Image from Discovery Education's Clip Art Gallery created by Mark A. Hicks, illustrator.
Brain & Behavior
Comments
Good link! Thank you!
Posted by: Ian | February 28, 2008 10:55 AM
Cool link.
"On any given day, sexual intercourse takes place 120 million times on earth."
Really? Assuming there are 6x10^9 people on earth, that's 0.02 times per person per day. Now, I don't know much about the field, but if even on person in four is sexually active, that's 0.08 times per sexually active person per day - once every twelve days. I am surprised this number is so small.
Posted by: Marc | February 28, 2008 11:47 AM
Marc, you must not be married.
(Note to my wife: I'm kidding!)
(or am I?)
Posted by: Sven DiMilo | February 28, 2008 1:04 PM
4. Your nose can remember 50,000 different scents.
It seems this "fun fact" should instead read either "Your nose can distinguish 50,000 different scents" or "Your brian can remember 50,000 different scents." I'm fairly certain my nose can't remember anything.
Posted by: Ellery | February 28, 2008 3:56 PM
Ugh, that should be brain, not brian... I blame my nose.
Posted by: Ellery | February 28, 2008 3:58 PM
perhaps your brain is named brian.
Posted by: cephyn | February 29, 2008 5:27 PM
Don't be silly! My brain is named Ed.
Posted by: Ellery | February 29, 2008 10:38 PM
Well the first line is pretty silly and ignorant - "The largest cell in the human body is the female egg and the smallest is the male sperm."
Thats not really the case - a mature sperm cell is 60 micrometers in length. Many cells are small then that, including your blodcells.
A female egg on the other hand consists of many cells and grows during the menstrual cycle - near ovulation the egg has around 600 cells. Its like saying your 'brian'/nose is one big cell.
Too bad people make these things up, because there are plenty of funny stuff about our body as it is.
Posted by: Mike Barnkob | March 13, 2008 12:49 PM
I'd be leery about blogging a link to a site with such uncredited "facts". These same "facts" are all over the web, often without attribution for example at:
http://bebo.com/BlogView (http://tinyurl.com/26r7t8)
Some of them are downright wrong, such as the facial hair growing faster than other body hair. At least one (the smile vs. frown) dates back to 1995 according to Snopes:
http://www.snopes.com/science/smile.asp
This "brain is 80% water" claim rather vague to actually tell us anything useful about the brain.
It would be nice to see some sources for the claims.
Posted by: Ian | March 14, 2008 3:22 PM
Sorry, Mike, but looking up "ovum" on Wikipedia and then clicking through to its references (a good idea with Wikipedia), every reference refers to the mature human ovum as the largest body cell (singular). Where in the world did you read that it was 600 cells?
If you count the flagellum, a human sperm may be longer than many cells but its body is quite small, such that in terms of volume it may well be the smallest.
Posted by: idlemind | March 17, 2008 5:04 AM
Hi Idlemind -
This is a interesting discussion.
I think I found the same article on Wikipedia and while there are references noted at the cells size (which the article says is between 100 to 200 micrometers), there are non listed for the fact that it should be the biggest cell in the body.
I looked up the size of oocytes in Medical Physiology (p. 1156, 2th edition, 2005 by Boron & Boulpap), where the size is listed as 120 micrometer, and in Histologi (p. 633, 2002 by Geneser) where the final size of the oocyte is listed as 125 micrometers (the darn things grow and float around all the time). The only link in the wikipedia article that lists the size as 200 micrometers is Grays Anatomy fra 1918, so I think its fair to say that the diameter is ca. 125 micrometers.
I know this makes a grown oocyte one of the biggest cells in the body - but I really do doubt that its biggest in either diameter or volume. Some of the biggest motor neurons in the medulla spinalis have a diameter of up to 135 micrometers (p. 343, Histologi, Geneser) and can be up to 1 meters long (p. 411, Essetial Cell Biology, Alberts et al). I can't really find details about the volume of neurons, but the size alone makes it hard to believe that they should contain less the a full grown oocyte.
As for sperm cells the flagellum is pretty essential, so I do think it should be counted. It is part of the cell as such and without it the sperm wouldn't really function. But if you leave it out, the head is about 5 micrometers and flat - but even then I would believe that thrombocyts are even smaller (Wikipedia lists them as 1-3 micrometers).
I must apologize for the 600 cell part - I was counting the entire follicle and the supporting cells around the oocyte, which is around 600 near ovulation. I thought the authors of the '100 facts' was referring to this unit, without realizing that the oocyte in it self is big enough to make the misunderstanding occur.
Posted by: Mike Barnkob | March 17, 2008 7:19 AM