The Brain

            
            
            
            
             The human body is divided into many different parts called .
             All of the parts are controlled by an organ called the brain, .
             which is located in the head. The brain weighs about 2.75 pounds, and .
             has a whitish-pink appearance. The brain is made up of many cells, .
             and is the control centre of the body. The brain flashes messages out .
             to all the other parts of the body. The messages travel in very fine .
             threads called nerves. The nerves and the brain make up a system .
             somewhat like telephone poles carrying wires across the city. This is .
             called the nervous system.
             The nerves in the body don't just send messages from the brain .
             to the organs, but also send messages from the eyes, ears, skin and .
             other organs back to your brain. Some nerves are linked directly to .
             the brain. Others have to reach the brain through a sort of power .
             line down the back, called the spinal cord. The brain and spinal cord .
             make up the central nervous system.
             The brain doesn't just control your organs, but also can think .
             and remember. That part of the brain is called the mind.
             PROTECTING THE BRAIN .
             Twenty-eight bones make up the skull. Eight of these bones .
             are interlocking plates. These plates form the cranium. The cranium .
             provides maximum protection with minimum weight, the ideal .
             combination. The other twenty bones make up the face, jaw and other .
             parts of the skull. .
             Another way the brain keeps it self safe is by keeping itself .
             in liquid. Nearly one fifth of the blood pumped by the heart is sent .
             to the brain. The brain then sends the blood through an intricate .
             network of blood vessels to where the blood is needed. Specialized .
             blood vessels called choroid plexuses produce a protective .
             cerebrospinal fluid. This fluid is what the brain literally floats .
             in. .
             .
             A third protective measure taken by the brain is called the .
             blood brain barrier. This barrier consists of a network of unique .
             capillaries. These capillaries are filters for harmful chemicals .