What is the difference between the Central Nervous System (CNS) & the Peripheral Nervous System (PNS)?
The brain and the spinal cord are considered to be the CNS. The nerves that branch out from the CNS and send communications back & forth with other parts of the body make up the PNS. The PNS can be further subdivided into the somatic nervous system and the autonomic nervous system. The somatic system includes nerves that connect the brain & spinal cord to receptors in the skin and skeletal muscles & is involved in conscious activities. We can think of the autonomic nervous system as an “automatic” system of nerves that connect the brain & spinal cord to various organs to control unconscious activities. It includes nerve fibers that arouse the body for stress or “fight or flight” responses and then returns the body to a resting state. (See question 4 for more information on the autonomic nervous system.) 2. Is there a difference between the terms “neuron” & “nerve” or can either word be used? Yes, there is a difference between a neuron & a nerve. The term “neuron” refers to a single cel
