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تاريخ التسجيل : 18/11/2009
 | موضوع: Human head and brain size  الجمعة نوفمبر 27, 2009 11:00 pm | |
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Human head and brain size
The human head contains 22 bones, consisting the cranium and the facial bones. The cranium is formed by 8 bones: the frontal bone, two parietal bones, two temporal bones, the occipital bone in the back, the ethmoid bone behind the nose, and the sphenoid bone. The face consists of 14 bones including the maxilla (upper jaw) and mandible (lower jaw). (The skull has many little holes in its base which allow the cranial nerves to travel to their destinations.)
The cranium protects the brain, which, for an average adult male weighs about 1400 gram (49oz). The brain of Russian novelist Turgenev, weighed 2021g (71oz), Bismarck's brain weighed 1807g (64oz), while that of famous French statesman Gambetta was only 1294g (46oz). Female average brain mass is slightly less than that of males. The largest woman's brain recorded weighed 1742g (61oz). Einstein's brain was of average size.
An elephant's brain weighs 5000g (176oz or 11 lb), a whale's 10000g (352oz or 22lb). In proportion to the body, the whale has a much smaller brain than man. This seem to give man the edge, until it was discovered that the dwarf monkey has 1g of brain per 27g (0.95oz) of body, and the capuchin monkey has 1g of brain per 17,5g body, whereas man has 1 gram of brain to 44g of body.
Most scientists believe that "photographic memory" is a myth. Clever people train their brains to remember well. In fact, as humans we simply do not remember things well. Of the three beings known to be able to recognise themselves in the mirror, the orangutan, the dolphin and the human, only the latter turns around and instantly cannot remember what his/her own face looks like. (Try drawing a picture of yourself without looking in the mirror:)
Brain power
The human brains consists of more than 100 billion neurons (nerve cells) through which the brain's commands are sent in the form of electric pulses. These pulses travel at more than 400 km/h (250 mph), creating enough electricity to power a lightbulb. The brain consumes more energy than any other organ, burning up a whopping one-fifth of the food we take in.
It is estimated that the mental capacity of a 100-year old human with perfect memory could be represented by computer with 10 to the power of 15 bits (one petabit). At the current rate of computer chip development, that figure can be reached in about 35 years. However, that represents just memory capacity, not the extremely complex processes of thought creation and emotions.
But consider this: for all the complexity of the brain, you still have only one thought at a time. Make it a positive thought.
Factoids
One-quarter of the brains in used to control the eye. We actually see with our brains, with the eyes basically being cameras.
You're born with 300 bones, but when you get to be an adult, you only have 206. | |
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