what makes up the peripheral nervous system

The peripheral nervous system (PNS) is made up of all the nerves and associated structures that lie outside the brain and spinal cord.

Core components

• Peripheral nerves : Bundles of long neuron fibers (axons) that run between the central nervous system (CNS) and the rest of the body.

• Spinal nerves : Nerves that emerge from the spinal cord and go to the skin, muscles, and organs.

• Cranial nerves : Nerves (mainly cranial nerves III–XII) that emerge from the brain and brainstem and supply the head, neck, and some internal organs.

• Ganglia : Clusters of neuron cell bodies located along these nerves that act as relay and processing stations.

• Connective tissue and blood vessels : Support and nourish the nerve fibers within each nerve.

Functional divisions

• Somatic nervous system : The “voluntary” part; carries sensory information from skin and joints to the CNS and motor commands from the CNS to skeletal muscles.

• Autonomic nervous system : The “involuntary” part; controls smooth muscle, heart, and glands, and includes:
  • Sympathetic division (“fight or flight”).

* Parasympathetic division (“rest and digest”).

Microscopic elements

Within these nerves, you find:

• Neurons : The basic cells that generate and conduct electrical signals.

• Axons : Long projections that carry signals along the length of a nerve.

• Dendrites : Short, branch-like extensions that receive incoming signals.

• Myelin : A fatty insulating layer around many axons that speeds up signal conduction.

Simple takeaway

If you imagine the CNS (brain and spinal cord) as a central computer, the peripheral nervous system is all the wiring—nerves, ganglia, and supporting tissues—that branch out to every part of the body to bring information in and send commands out.

Information gathered from public forums or data available on the internet and portrayed here.