Nervous System

The human body is made up primarily of bones, muscles, and nerves. Bones provide support and structure, muscles allow for movement, and nerves act as a communication system. The nervous system is composed of two sets of nerves and nerve centers: the cerebro-spinal system and the sympathetic system. The cerebro-spinal system includes the brain, spinal cord, cranial nerves, and spinal nerves, which are all connected to the central axis. The sensory nerve transmits impressions from the central organ to effect specific changes in the body. Movement is caused by a stimulus applied to the ends of sensory nerves, which creates molecular changes that are transmitted along fibers to the central organ. This disturbance is then transmitted along motor nerves to specific muscles, causing them to contract and relax in a reflex action.

Reflex actions are responsible for most human activity, and habits or actions become embodied in the nervous structure through repetitive practice. The struggle between will and reflex action can lead to physical changes, with reflex action often winning out. Weak-willed individuals may be affected immediately by reflex actions that lead to suffering. Association and reflex action are essential to the appreciation of music and the conversion of sound sensations into feelings and emotions. Every sound in music carries with it a stream of associated feelings.