The Peripheral Nervous System

The nervous system is one of the smallest yet one of the, if not the most, complex systems in the human body. It can be broken down into two main subdivisions, the central nervous system (CNS) and the peripheral nervous system (PNS). The central nervous system contains about 85 billion neurons and includes the spinal cord and brain. It is considered the control center of the body and processes all types of incoming sensory information. The peripheral nervous system is composed of all the other tissue outside of the central nervous system. It can be broken down into a somatic nervous system (SNS), an autonomic nervous system (ANS), and an enteric nervous system (ENT). Components that are involved in physical sensation come from both the central nervous system and the peripheral nervous system. To begin with, the somatic nervous system, which is part of the peripheral nervous system, is made up of nerve fibers that detect and carry information
In the peripheral nervous system, the somatic nervous system picks up a sensation, for example touching an extremely hot surface, and sends the information through sensory neurons, passing from neuron to neuron, until it reached the central nervous system. The central nervous system, consisting of the brain and spinal cord, acts as a “control center” of sorts and processes the information from the sensory neuron through cranial and spinal nerves and through a process called integration. In our example it receives the information that the surface is hot and will conduct an appropriate response, to yank your hand back form the hot surface. Now that the information has been integrated the nervous system will give feedback as a motor response and activate effectors that will contract the correct skeletal muscles to remove your hand from the hot