David Jonaitis, age 9, of Old Bridge, N.J., for his question:
HOW DOES YOUR BRAIN WORK?
A German physician by the name of Hans Berger demonstrated in 1929 that the brain generates a small electrical current which can be measured with the proper equipment. He also found that when the brain is relatively at rest, the current is small. When there is an increase in the mental activity, Dr. Berger discovered, the current increases.
It is necessary for the body to have some organ that is much like a control center or a computer station. Such a center is necessary to co ordinate the working together of the various parts of the body and the brain is that control center.
Your brain enables you to think. It also controls your muscle movements and helps you to distinguish smells, sounds, shapes, words, colors and such feelings as hot and cold.
We don't know exactly what makes a human brain work in a much more complex and ''intelligent'' way than the brains of other animals. Size has little or nothing to do with the difference in ability. There is some relationship, however, between ability and the proportion of the weight of the brain to the total weight of the body. Man's brain weighs about one fortieth of his total body weight while the brain of a whale is only one twelve thousandth of the total body weight.
Your brain is actually the enlarged end of your spinal cord. It is divided into three divisions: the forebrain (which includes the cerebrum and interbrain), the midbrain and the hindbrain (where the pons, medulla oblongata and cerebellum are found).
Largest part of the brain is the cerebrum where the frontal lobes handle chores related to thinking, speaking and the control of movement. The thalamus of the interbrain controls sensory functions, while the midbrain is concerned with visual and auditory details.
The cerebellum, located below the posterior section of the cerebrum, is primarily concerned with the function of maintaining harmony and balance among the muscles. In addition to co ordinating the muscles, the cerebellum also maintains a constant alertness which makes upright posture possible.
Below the cerebellum is the medulla oblongata, the part of the brain that controls the involuntary muscles and functions such as breathing, blood circulation and the processes of digestion.
The brain is located in the skull and is very well protected. Surrounding the brain are the meninges. These membranes are made up of three layers. The meninges form spaces for the cerebrospinal fluid. This liquid helps to cushion the brain and spinal cord against injury and to keep nerve tissue moist and lubricated.