Brain
Brain
This is the portion of the central nervous system contained within the skull, and weighs about 1400 g (3 lb) in adults. It is divided into three main parts: the cerebrum, the cerebellum and the brainstem.
The cerebrum is the largest part of the brain, and is a mass of convoluted grey and white matter divided by a deep fissure into two halves or hemispheres, which are linked by a thick band of nerve fibers.
The cerebrum is responsible for most of the 'higher' functions of the brain, such as understanding the messages that the senses are sending to the brain (sensory interpretation) and initiating movement (motor actions).
It is also the seat of many mental activities such as logical thought and emotions. The cerebellum is situated towards the back of the skull, and again is divided into two hemispheres. It is mostly responsible for coordinating movement.
The brainstem connects the rest of the brain with the upper part of the spinal cord, and performs motor, sensory and reflex functions, automatic responses to certain stimuli, such as withdrawing your hand from a hot surface before you become aware of the heat.
The left side of the brain controls the right side of the body, and in 90 per cent of the population is the dominant hemisphere for speech and writing. The left hemisphere is also thought to be more analytical.
The right side of the brain interprets visual stimuli and sounds other than speech, such as music. Here lays our ability to think visually and to use our imagination.
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