After reading this article you will learn about the working of simple reflex with the help of a diagram.
Reflex actions are not learnt but are present from birth. They are essentially concerned with the preservation or protection of the organisms. Most reflexes are controlled by the spinal cord; some of course by the other centres.
The following example explains the working of the simple reflex:
If a stimulus (a bright flash of light) impinges on a receptor organ (the eye) it activates the nerve fibres, and the nerve impulses are conducted to the spinal cord.
The spinal cord, in turn, activates a set of motor nerve fibres resulting in the closure of the eye. This is called a pupillary reflex or the eye blink response. The child at birth is capable of quite a few reflex actions which essentially serve the function of protection from injury. As the child grows, more reflexes appear. Reflex actions have a very short reaction-time.
However, all human actions are not so simple. Gradually more complex actions and responses develop. These, of course, take a longer time because they involve a greater degree of complexity, and coordination, for they don’t occur at the level of the spinal cord but at the level of the brain.
The brain, therefore, is the centre for all complex activities, including those within the brain. There are different centres concerned with different types of activities. As the science of neurology has developed we have come to know more and more about the marvelous capacities of the human brain, but even today we haven’t understood much of its nature and functioning.