Peripheral Nervous System, Nerve Regeneration, and Dermatomes

Structure of a neuron in the peripheral nervous system?

1. epineurium

2. perineurium

   1. fascicle

3. endoneurium

What is the epineurium made of?

dense irregular connective tissue

What is the function of the epineurium?

physically protect the nerve, epsecially against abrasion

What is the perineurium made of?

dense connective tissue

What is the function of the perineurium?

separate the nerve into regions known as fascicle

What is a fascicle?

units of thousands of axons

What is endoneurium made of?

arealor connective tissue

What is the function of endoneurium?

provide nutrients to the axon

Does a nerve regenerate if it completely dies?

No, if the cell body dies then it will not grow back

Can a nerve ever regenerate?

Yes, if the axon is severed the neuron still may be able to regenerate

What must a person do in order to regenerate their severed nerves?

Physical therapy

Explain the importance of certain therapy to nerve regeneration

enforcing the ‘use it or lose it’ theory. action potential going down the muscles, the more likely the axons are to regenerating. If a person does not commit to PT, no AP will be sent, axons will not be used and no regeneration will take place.

The chances of regeneration and regaining physical abilities is much higher if AP fires and use axons to establish neural pathways.

What does the ‘tingling sensation’ mean?

Brain telling you something is wrong with nerve in that area. Oxygen is not being delivered to that area of the body. The nerves now sending information back to the brain, alerting that something is wrong and need to act on it.

Why does the tingling sensation not go away for diabetic people?

When it comes to diabetes, you have individuals who are not able to bring their blood glucose levels back down. That causes damage to not only the blood vessels in the area, it also causes damage to the neurons in that area. People lose sensation in their extremities first.

What are dermatomes?

regions of the skin that are innervated by a particular spinal nerve, these dermatomes are going to be specific regions that we are able to pick up sensory information from

Importance of dermatomes?

• diagnostic purposes

• locating spinal cord or nerve injuries

• tracking shingles

• administering targeted anesthesia

• evaluating disease progression

Cause of shingles?

chicken pox virus that belongs to the herpes family, we do not have a cure for herpes. Once you are over the symptoms, the virus hides inside the dorsal roots ganglion. They come back when the host body gets weaker. As a person ages, they will get shingles.

What is the connection of dermatomes and shingles?

shingles rash affects the nerves from the spinal cord, following the path of the dermatomes