Nervous System Functions
The highly complex and efficient nervous system in human beings performs a great variety of voluntary as well as involuntary functions in the body that are related to communication, and the coordination of various vital mechanisms. All the parts and subsystems work effectively in close interaction with one another for the accomplishment of a particular task, such as breathing, swallowing, sexual arousal, body organ movements, respiration, and so on. Some of the most important functions of the human nervous system can be summarized as under:
General Functions of Human Nervous System
One of the general functions of nervous system is to sense specific information in the form of stimuli not only in the internal environment but also in the surroundings. For example, you go into a big hall and happen to see a wooden structure on the stage that has a flat top supported on four legs. It simply means, you have sensed information with the help of your vision, and the same piece of information will be sent to higher parts of the brain for their interpretation and integration.
After sensing particular information, the signals are transmitted to other specialized parts of the nervous system to be interpreted and understood. In the above example, the wooden structure would be interpreted as a table. Take another example, in which you happen to see your friend after twenty years; the information signals will be interpreted in the brain and you will come to recognize them as your close acquaintance.
Responding to Information
After the interpretation of specific information, a specialized center in your brain will generate a response which will travel through nerves to the target organ. In the example of a wooden structure on the stage, once you have recognized it as a table, an appropriate response will be generated. In this case, if you are the chief guest, you will go to the stage and sit on the chair that is placed beside it.
Other Functions of Human Nervous System
One of the most basic nervous system functions is to act as a fast communication highway among different nearby and distant organs or structures of the body. It is quite logical to say that interaction of different organs and organ systems in your body has become a possibility only because of the mutual communication of different constituent parts of these larger complex units.
Cognition is an important nervous system function and it is only because of cognition that you can memorize things, develop attention, learn, reason, solve problems, make decisions, and produce & understand language, and so on.
Organize and Execute Actions
It is because of the voluntary control of humans over motor neurons that they can organize and execute any action they like. In the absence of such a faculty, you would have been unable to perform any task at your own will, and the entire life would have become a boring stuff. In the generation of some desired action or movement, there has to be ensured cooperation between the musculoskeletal system and the central nervous system involving the processes of cognition, physics, mechanics, information processing and coordination.
Conscious and Unconscious Control of Breathing
Primarily, breathing is a life supporting activity, but you can also bring it under your conscious control for the accomplishment of other important tasks of routine life, such as vocal training or speech, swimming, cardio fitness and pranayama, etc. The involuntary mechanism of breathing is also essential for your life because if the process of gaseous exchange were only under your voluntary control, a sleeping individual would have died owing to the cessation of this respiratory activity.
Did you ever imagine that sexual attraction and arousal is an involuntary mechanism? The execution of this natural phenomenon is purely owed to the functionality and effectiveness of your nervous system, particularly, an autonomous mechanism that ensures the continuation of the generation of every creature on the planet earth. However, quite interestingly, it can also be brought under voluntary control by diverting the attention from a source of sexual attraction. According to the teachings of major religions of the world, an individual has to bring sexual desire and the practice of mating under their voluntary control, so that there could be established peace and order in the world.
Just think, if digestion were a voluntary process, what would you do to digest and extract energy out of the delicious food you consume on daily basis? Beyond any doubt, it would have been a very laborious task and everyone would be busy for many long hours while digesting, absorbing and breaking down food to extract energy. In that case, your life would have been limited to obtaining, digesting and excreting (undigested) organic materials; and nothing else at all!
The undigested food particles and several other harmful substances, produced during the execution of miscellaneous processes in the body, have to be excreted at any case; and this is done with the help of an involuntary mechanism. So, the nervous system comes to your rescue once again and delivers you from this, otherwise, very critical situation.
In its vital importance, heart is considered only secondary to your master organ, the brain, because it is assigned the task of the circulation of blood in your body so that materials could be transported from one place to another and the supply of oxygen is ensured to each and every cell of the body. If, owing to any unfortunate circumstances, your heart stops breathing, the brain cells will be damaged and ultimately die, thus ending your life itself. The continuous and uninterrupted breathing of your heart is solely owed to the indispensable value of your nervous system.
There is an automatic and involuntarily controlled mechanism for the adjustment of the size of pupil in response to the conditions of varying light intensity. In the process, when the intensity of light is high, the pupil contracts letting less amount of light go in while, on the other hand, in low light intensity environments, the pupil gets constricted to let more amount of light go in. Even more surprisingly, as soon as you go to sleep, your pupils get contracted as there is no need to see anything while sleeping.
You might be acquainted with the fact that the process of digestion start as soon as a morsel of food enters your mouth. But do you know how does this happen? It is simply because of the initiative taken by your nervous system leading to the production and pouring of saliva in the mouth cavity. There are enzymes, such as salivary amylase, present in this salivary fluid that result in the digestion of organic compounds in the diet, for example, carbohydrates.