Role of Sense Organs in Receiving and Transferring Information to Brain !
We known that the role of brain in perceiving and evaluating the experiences is undoubtedly crucial. But it is equally important to know the role of sense organs in receiving the information and transferring the same to the concerned part of brain.
It is a well known fact that the human being has five sense organs, viz., eye, ear, nose, tongue and skin. These sense organs are the instruments by which the mind is brought into relation with external world. Without these sense organs no information can reach the brain. That is the reason they are called as the ‘Gateways of knowledge’.
In this background it may be described that,’ sensation is a process of shifting of information from sense organs to the brain’.
Let us understand physiological process underlying in any sensation. The sense organs are connected by sensory cranial nerves. Each sense organ will have receptor neurons in it. When a stimulus from the environment reaches the sense organ, the receptor neuron will receive it and converts the same into a form of neural energy, and shift it to the concerned part of brain through the sensory nerve. The brain will evaluate this energy on the basis of past experiences and other intellectual abilities and interpret it. Hence, this ‘process of shifting of stimulus from sense organ to the brain through sensory nerve is called sensation’.
The sense organs and sensations are as follows:
Eye- vision, Ear- audition, Nose- olfaction, Tongue- gustatory and Skin- tactile sensation. Each of these sense organs has a distinct function to perform, i.e. ear can only hear, eye can only see but cannot hear and so on.
The latest studies have shown that in addition to the above five, there are three more sensations viz., static sensation for body balance, kinesthetic sensation for muscular movements and organic sensation for inner organs.
The receptors of sensory organs like eye, ear, nose, tongue and skin are placed superficially and can receive stimuli from outside the body, whereas the receptors in static, kinesthetic, and organic are placed in inner portions of the organs.
They are stimulated by conditions within the organism and its cavity. There are some receptors which are located between the internal and external surfaces in muscles, tendons, joints, semi- circular canals and vestibules of the ear. They give rise to kinesthetic and static sensations.
The behaviour of the organism is directly influenced by these sensations. In turn the sensations result only from the stimuli that reach cortex and are consciously perceived. For good sensations, healthy sense organs are essential. But many times we come across people suffering from many sensory defects. These defects may be related to stimuli, sense organs, sensory nerves or brain.
The behaviour of the individual will be healthy if there are no problems. On the other hand sensory defects like blindness, colour blindness, deafness, etc. may affect the behaviour. Sometimes the patients suffering from mental illness like conversion hysteria may also complain of sensory problems.
Hence, it is important for the nurses to have clear knowledge of sensations, sensory organs and the sensory defects, because when a patient with some sensory defects approach her, she can understand his behaviour and problems and help the patient to get a better treatment and to lead an adjusted life.