Nervous System

The physical structure of the human body is composed of mainly bones, muscles and nerves. The bones support and maintain the physical form. The muscles move it and the nerves like telephone wires guide the functions. The nervous system which we are more concerned consists of two sets of nerves and nerve centres which are connected together. These are the cerebro-spinal system and the sympathetic system. The former consists of the cerebro-spinal axis composed of the brain, the spinal cord, the cranial and the spinal nerves which are connected with the axis. The latter consists of two branches: the sensory and the motor. The sensory nerve carries away that impression from the central organ to effect specific changes in certain portions of the body. In explaining the above process, we can also state that a movement of the body or any part of it is to be regarded as the effect of a stimulus applied to the ends of sensory nerves, which set up a molecular charge in their substance and the change is propagated from molecule to molecule along the fibres to the central organ with which they are connected.

The molecular activity of the sensory nerve sets up changes of a like order in the fibres and cells of the central organ. Such disturbance is transmitted along the motor nerves which pass from the central organ to certain muscles. A similar disturbance is set up in the muscular fibres which contract and relax accordingly. This phenomenon is known as the reflex action. Some of the experiences of reflex action in day to day life are:

Most of human activity is due to reflex action. The brain directs the human body to have an infinite number of reflex actions. A person gets into a habit after a series of repetitive but similar action. For example, a soldier takes a long time to learn his drill such as an attitude of 'Attention' but after sometime, the sound 'Attention' gives rise to the act even without his knowledge. There is a joke about a soldier who dropped his plate of dinner after a sudden call of 'Attention'. When certain actions are practiced thoroughly for a long time, they become habits and these habits or actions become embodied in the main nervous structure.

Physical change and the struggle between the will and the reflex action is so doubtful and as a result, it is the reflex action which gets the upper hand. There are some people who are moved to tears at the first sight of some action in a film or stage drama without being able to control their feelings. The men of weak will and nerve are affected immediately through reflex action which are set up within them in the areas of epidermis and lead to suffering. This shows of a piano, which at the mere touch of any agent, finger or the stick gives rise to some sounds and feelings. This is why sometimes during the still hours of the night, mewing of cats is mistaken for the cry of little babies and roused tender feelings. The deep sound caused by the passing of a strong current of wind through the window, sometimes remind us of the hooting of an owl. Hence association and reflex action play a very important part in appreciation of music, in converting sensation of sound into respective feelings and emotions. It is observed that every sound in music carries with it a stream of associated feelings.