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Reflexes

The body often needs to react to a change to keep a state of balance between the inside of the body and external environments, these reactions are known as Homeostasis and often the body reacts to these changes through the Nervous System. The Nervous system can be defined as “the vast network of cells specialized to carry out information, in the form of nerve impulse, to and from all parts of the body in order to bring about bodily functions” (Ward, B. 1981).   These impulses are carried out by nerve cells, also known as neurons. Although there are different types of neurons, they all have a similar structure, with a large cell body and a long axon to carry the impulse along. The Nervous system is made up of two parts; the central nervous system and the peripheral system (appendix 1). Under the peripheral system is the autonomic system whose role is to keep things in a steady state so that all the body organs work efficiently. The nerves for this system run alongside the spinal cord within the backbone, and run through the heart, lungs, gut, liver, kidneys and bladder. The autonomic system controls involuntary movements and can be divided into either the sensory (afferent) division or the motor (efferent) division (appendix 1). The motor division is responsible for transmitting impulses from the central nervous system to the peripheral organs to cause an action or movement. The motor (efferent system) can also be divided into two divisions; the sympathetic system and parasympathetic system (appendix 1). The sympathetic system involves the fight or flight response which mobilises body systems during emergency situations. The Parasympathetic system converses energy and promotes non emergency functions. Most of our normal body functions are controlled by the Parasympathetic system; however the Sympathetic system takes over when the body experiences a sudden change such as excitement or fear.
A reflex is a “body reaction that occurs quickly and automatically, in...