The brain occupies most of the cranial cavity. It accounts for about 2% of the adult's weight, that is, 1.2 ~ 1.6 kg. The brain weight of men is slightly larger than that of women, which has nothing to do with weight. The brain contains about 654.38+0.4 billion nerve cells, accounting for about one tenth of brain cells, and the remaining 90% are called glial cells. Glial cells have many functions, such as providing nutrition for nerve cells, forming myelin sheath and improving conduction speed.
People often say that "only about one tenth of the brain is effectively used", which may be a misunderstanding from an era when the function of glial cells is not fully understood. It is believed that only nerve cells are working in the brain, that is, there is no credible theory about the development of human brain 10%.
Brain activity:
If you can convert brain activity into electrical energy, it is equivalent to the power of a 20-watt light bulb.
According to some measurements by neuroscientists, the circuit of nerve cells in the human brain is more complicated 1400 times than the telephone network all over the world today.
Every second, there are 654.38+ million different chemical reactions in the human brain.
Only 1% of the information continuously received by the five sensory organs of the human body is processed by the brain, and the remaining 99% is filtered out.
The fastest transmission speed of nerve impulses between brain nerve cells is more than 400 kilometers per hour.
The brain is surrounded by a membrane containing veins and arteries, which is filled with sensory nerves. But the brain itself has no feeling, even if the brain is divided into two, people will not feel pain.
The average human brain accounts for 2% of the total body weight, but it needs to use 25% of the oxygen used by the whole body, while the kidney needs 12% and the heart needs 7%. The transmission speed of nerve signals in nerve or muscle fibers can be as high as 200 miles per hour.
The number of human brain cells is more than twice the total population of the world, and it can process 86 million pieces of information every day, and its memory stores more information than any electronic computer.
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