THE CENTRAL NERVOUS SYSTEM in our bodies is actually two systems in one, consisting of the nerves in the brain and those in the spinal cord. These two key nerve centers are encased in the skull and the vertebral canal of the spine.

To understand how they connect into the network that enables sensation and vitality, think of your body as a tree with a trunk and outward-stretching branches that divide into even smaller extensions. The “lower branches” on your tree are the “peripherals,” for example the nerves in your feet and your hands.

The peripheral nervous system (PNS) consists of the nerves outside the brain and spinal cord. The main function of the PNS is to connect the central nervous system (CNS) to the limbs and organs, essentially serving as a relay between the brain and spinal cord and the rest of the body, including the hands and feet. Unlike the CNS, the peripherals are not protected by the vertebral column and skull, or by the blood-brain barrier, which leaves the peripheral system exposed to toxins and mechanical injuries.   

How the peripheral nerves function

There are two types of these “extender” nerves.  One type, the autonomic peripherals, perform -- as the word “auto” might indicate — to control body functions without our consciously telling them to do such tasks as restrict our pupils in bright sunlight, or instantly warn us when the kitchen stove is hot.

Other peripheral nerves fall into the somatic peripherals category. The somatics can be guided by commands we consciously give our brains, i.e. “Pick up that frying pan on the stove (but use a potholder, and if you don’t, you’re gonna feel it, pal…”). The commands along this somatic peripheral system send signals from the brain to the organs, including the muscles in your hands and feet, and send back signals on the variety of sensations those hands and feet are experiencing. You step on a sharp object, your brain knows to say “ouch.”

Peripheral Neuropathy

Nerves in smaller branches of the nervous system can be damaged, whether by physical injury, or disease.  In the case of peripheral neuropathy, the branches in the feet and hands can suffer harm due to a variety of causes:  diabetes, alcohol consumption, the presence of heavy metals or other toxins, chemotherapy, a vitamin B-12 deficiency, and autoimmune or inflammatory conditions. The result is a diminishing of sensation in the extremities, a numbness, tingling, or -- in some cases -- the heightened sensation of acute and chronic pain. 

Either way, when peripheral nerves send signals that are impaired or indicate something is wrong, your doctor can diagnosis the problem and suggest some remedies. Because your peripheral nerves are a direct link to the physical world, understanding how to restore their healthy operation is vital for your well-being.

Sources:

U.S. National Library of Medicine/Pub Med Health: “How Does The Nervous System Work?” https://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0072574/

Wikipedia: Peripheral Nervous System https://en.wikipedia.org/wiki/Peripheral_nervous_system