Are the dorsal roots parts of the peripheral nervous system?

[Radium]

Hi:

Are the dorsal roots parts of the peripheral nervous system?


Thanks,

Radium

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[facetguy]

Yes.

 

[Radium]

Yes.

Is a dorsal root part of the somatic or visceral nervous system?

This is not a homework/test question. Just a question out of my curiousity.

 

[Dr latif]

Your question "Is a dorsal root part of the somatic or visceral nervous system?" is wrong

the nervous system is subdivided into central, peripheral and autonomic.
the way you ask somatic and visceral is really not correct.
Visceral usually refers to the autonomic part which supplies the viscera (abdominal organs and gut) which is carried in part by spinal nerves and in part by cranial nerves (Vagus CN X)

A dorsal root is part of the spinal nerve is always a mixed nerve (sensory & motor) as soon as the spinal nerve exits the spinal foramen it divides into a ventral root that innervate the ventral part of the body.
The ventral roots make the cervical, brachial, lumbar, and sacral plexus as well as the intercostal nerves are all ventral roots.
The dorsal root goes to the back to supply the muscles and skin of the back, all of these nerves (except the greater occipital) are not named they go by numbers, C2, T4 etc...

 

[Vader]

The spinal nerves are formed from the dorsal and ventral roots, carrying sensory & motor fibers, respectively. The spinal nerves divide into dorsal and ventral rami (or singular = ramus) that carry both sensory & motor fibers to the dorsal or ventral parts of the body.

The preganglion sympathetic neurons project fibers through the ventral roots of the thoraco-lumbar region, travel through the white rami communicans and synapse on post-ganlionic neurons that are located in the sympathetic ganglia. The post-ganglionic neurons then project fibers out the gray rami communicans back to the spinal nerves, where they travel out to the body.

Clinically, you can get Horner's syndrome (ptosis, miosis, anhydrosis) from reduced sympathetic outflow, i.e. from a lesion in one of the cervical sympathetic ganglia.

 

[Radium]

Your question "Is a dorsal root part of the somatic or visceral nervous system?" is wrong

the nervous system is subdivided into central, peripheral and autonomic.
the way you ask somatic and visceral is really not correct.
Visceral usually refers to the autonomic part which supplies the viscera (abdominal organs and gut) which is carried in part by spinal nerves and in part by cranial nerves (Vagus CN X)

A dorsal root is part of the spinal nerve is always a mixed nerve (sensory & motor) as soon as the spinal nerve exits the spinal foramen it divides into a ventral root that innervate the ventral part of the body.
The ventral roots make the cervical, brachial, lumbar, and sacral plexus as well as the intercostal nerves are all ventral roots.
The dorsal root goes to the back to supply the muscles and skin of the back, all of these nerves (except the greater occipital) are not named they go by numbers, C2, T4 etc...

According to wikipedia, http://en.wikipedia.org/wiki/Somatic_nervous_system , the peripheral nervous system is divided into somatic and autonomic -- see the bottom of the page. Is the dorsal root part of the somatic nervous system?

Also, isn't the dorsal root purely-sensory and not motor?

 

[abcxyz0123]

read a book man, you just asked the same 2 ridiculous questions after these people gave you great, thorough answers.

 

[Radium]

read a book man, you just asked the same 2 ridiculous questions after these people gave you great, thorough answers.

I'm still confused. Sorry. Is a dorsal root part of the somatic nervous system?

The reason I ask is because I am looking for a sensory nerve root that is part of the peripheral somatic nervous system.

So far a dorsal root is a nerve root that is sensory and peripheral. But is it somatic? If not, then what is an example of a peripheral sensory somatic nerve root.

 

[stochastic]

The dorsal root of a given spinal level (C5, L4, etc) is purely sensory. The ventral root of a given spinal level is purely motor. Dorsal and ventral roots combine to form a mixed (sensory and motor) spinal nerve for each spinal level. Spinal nerves then divide into ventral and dorsal rami, which are still mixed (sensory and motor).

What other posters have said is generally true about the term visceral referring to the autonomic nervous system. However, my answer to your question as to whether the dorsal root is somatic or visceral is:

IT IS BOTH SOMATIC AND VISCERAL!

The dorsal root is comprised of centrally projecting axons of pseudounipolar dorsal root ganglion neurons whose peripheral axons innervate either somatic (cutaneous, muscle, tendon, etc) structures or visceral (GI tract, heart, lungs, etc) structures. Therefore, the dorsal root is a peripheral sensory nerve carrying both somatic sensory information and visceral sensory information.

I hope this helps.

 

[Radium]

The dorsal root of a given spinal level (C5, L4, etc) is purely sensory. The ventral root of a given spinal level is purely motor. Dorsal and ventral roots combine to form a mixed (sensory and motor) spinal nerve for each spinal level. Spinal nerves then divide into ventral and dorsal rami, which are still mixed (sensory and motor).

What other posters have said is generally true about the term visceral referring to the autonomic nervous system. However, my answer to your question as to whether the dorsal root is somatic or visceral is:

IT IS BOTH SOMATIC AND VISCERAL!

The dorsal root is comprised of centrally projecting axons of pseudounipolar dorsal root ganglion neurons whose peripheral axons innervate either somatic (cutaneous, muscle, tendon, etc) structures or visceral (GI tract, heart, lungs, etc) structures. Therefore, the dorsal root is a peripheral sensory nerve carrying both somatic sensory information and visceral sensory information.

I hope this helps.

Thanks for your response.