The nervous system, as described in Taber's Cyclopedic Dictionary, is"a system of extremely delicate nerve cells, elaborately interlaced with each other." More specifically, it functions to regulate and coordinate body activities, as well as to adjust to both external and internal environment changes. It is made up collectively of the brain, cranial nerves, spinal cord, spinal nerves, and other areas that help maintain reception and response to stimuli. Once a change in the body is detected, nerves carry this information to the brain via axons (a process of a neuron that conducts impulses away from a

The nervous system is composed of two main principal types of nerve cells: neurons and neuroglia. Neurons function in initiation and conduction of impulses whereas neuroglia function primarily as connecting and supporting tissue. In addition neuroglia also play an important role in the reaction of the nervous system to injury and infection. Yet these two types are not alone responsible for all messages sent throughout the body. Small spaces, known as synapses, are often found between neurons, cell bodies or other receptors. Therefore, in order for a nerve impulse to travel along a nerve path, it must cross a synapse. Chemical substances, otherwise known as neurotransmitters, are located in these synapses and are alerted when an impulse is nearby. These neurotransmitters then release an impulse to the dendrite (a branch of the neuron that receives and projects impulses to a cell body) of the NEXT neuron, which then allows nerve impulses to travel through the neural pathways. Neuroglia also serve a supporting role for neurons, but also help to protect the capillaries of the brain by regulating what is to be absorbed from the blood into the brain. Both neuroglia, but more so neurons will be referred to later in this paper.

As diagram 1 shows, both afferent and efferent nerves play a role in both the CNS and peripheral nervous systems. As previously stated, both afferent and efferent nerves are responsible for carrying out the functions of the body. Yet, while each has their own function, more commonly than not, both types of nerves will work together to accomplish an action. The afferent nerves act as the messenger while the efferent nerves respond to stimulus.

Raudsepp, Eugene. Left Brain / Right Brain Inventory. Survey handed out by Professor Chris Fitzgerald, Webster University Leiden, the Netherlands, 1998.

Within the biological approach, there are two major classes of mental disorders: 'major depressions' and 'schizophrenia.' Both are believed to be largely hereditary disorders, caused by functional and chemical abnormalities. Schizophrenia, the most abundant form of mental disorder, is biologically thought to be due to excessive activity in cortical pathways such as the hypothalamus, midbrain or frontal cortex. Symptoms include delusions, deranged thoughts and 'demented concepts of the self.' Drugs that reduce or block transmissions within the dopaminergic synapses (e.g. haloperidol or other antipsychotic drugs) are the most effective treatment for most types of schizophrenia. These drugs aim to reduce the amount of usable dopamine in the brain which tries not to cure the disease, but to reduce its symptoms. In contrast, drugs that increase synaptic transmission (such as amphetamines or high doses of cocaine) can cause paranoid/schizoid behaviour, even in normal humans.

cell body and towards the brain) and nerve fibres. These changes are then interpreted by brain receptors, which then send impulses back along nerve fibres to the body's sensory organs such as the eyes, ears and sensory receptors located in the skin, joints, or muscles. Thus, the nervous system acts like the information highway of the body in the sense that it receives all information pertaining to regulation of the body, and it also sends out impulses which aid our actions, coordination and homeostasis.

Approximately 90% of our current population is right-handed; 97% of the population is also left hemisphere dominant. Since the left hemisphere controls most of the right side of the body as well as many of our motor, verbal, logical and linear abilities, it is important that the Corpus Callosum is able to relay messages to the right hemisphere. Our right hemisphere, the holistic, emotional, representational and musical area of our brain, is also responsible for interpreting much of our visual stimuli. Should the Corpus Callosum be severed, as occurs in 'Split Brain' operations when it is cut to reduce epileptic seizur

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