All the things that we can sense have their origins in the PERIPHERAL NERVOUS SYSTEM. The peripheral nervous system is made up of all the nerves that are located outside the spinal cord. These nerves transport information to and from the central nervous system. The sensory cells are involved in carrying information from the peripheral nervous system to the central nervous system. The sensory cells include the cells that are responsible for sight, sound, smell, taste and pressure.<span />
Positive feedback loops are rarer than negative ones because of homeostasis, but they do occur. Negative feedback loops return to the set point in reverse, and positive feedback loops amplify a departure from the set point.
