Mark Murray, age 14, of Eugene, Oregon, for his question:
How does the brain work?
So far, the human mind has been unable to fathom all the secrets of the human brain. We know only how it works in a general sort of way and that certian functions are carried on in special areas. Recently a team of researchers learned something new about the left and right sides of the brain. However, what goeson in many other sections is still a mystery.
The three pound human brain is a miraculous package of about ten billion special nerve cells. It operates 24 hours a day on electrochemical energy and works somewhat like a super computer.
The basic working unit of the brain is the nerve cell, which has a main body called the neuron attached to long or short fibers called axons. It contains a balanced assortment of complex biochemicals and its multiple life processes are directed by nucleic acids, D:dA and RNA. The miraculous midget uses oxygen to create its own supply of electrochemical energy.
A delicate network of a billion or so nerve cells links every pinpoint on and inside the body with the brain. Their axons can relay 1,000 electri¬cal impulses per second. These signals to and from the brain can travel 350 feet per second. The brain is central headquarters of the body's fabulous built in communication system.
It receives a streaming multitude of signals from the sensory nerves ¬sorts, evaluates and judges them. Some news items are sent for storage in memory banks, others to creative centers. Motor nerves pulse the brain's decisions for action to teams of muscles. In moments of dagger, automatic actions are triggered faster than you can think.
About 90 per cent, or almost 2O billion of the nerves involved in the total communication system are crowded in the brain. This three pound miracle is housed under the skull bones and nourished by its own blood supply, which delivers 20 per cent of the total oxygen consumed. by the body.
The brain's wrinkled grey thinking cap is the cerebral cortex, a soft surface layer one eighth to one sixth of an inch thick. Here the in coming signals are processed and many decisions are made. The wrinkled cortex is grooved with several deeper fissures. In different regions there are brain centers that cope with sight, hearing and dozens of other separate functions.
The main fissure partitions the brain in a left and a right hemisphere. Communications with the left side of the body are linked with the right hemisphere. The left hemisphere has the centers that cope with the hand, arm, leg and other working parts on the right side of the body.
The centers of speech, hearing and many other functions have been located in their regions of the brain. Researchers are beginning to solve mysteries in the opposite hemispheres. These are linked by special fibers called the corpus callosum which exchanges a surprising amount of data and cooperation between the two sides. It was thought that the left hemi¬sphere, that copes with the right side of the body, must be the dominant one. Now we learn that the neglected right hemisphere contains the brain centers for the appreciation o€ music, perception and artistic talent ¬and creative imagination. The centers for logic and math, science and language are in the left hemisphere.