Brain
Definition
The brain is the part of the central nervous system located in the skull. It controls the mental processes and physical actions of a human being.
Description
The brain, along with the spinal cord and network of nerves, controls information flow throughout the body, voluntary actions such as walking, reading, and talking, and involuntary reactions such as breathing and digestion.
The human brain is a soft, shiny, grayish-white, mushroom-shaped structure. The brain of an average adult weighs about 3 lb (1.4 kg). At birth, the average infant's brain weighs 13.7 oz (390 g); by age 15, it has nearly reached full adult size. The brain is protected by the skull and a three-layered membrane called the meninges. The brain's surface is covered with many bright red arteries and bluish...
[The entire page is 1744 words long]
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