why every plexus emerge from anterior rami of spinal nerve not from posterior rami [you]

[M.shehab]

why every plexus emerge from anterior rami of spinal nerve not from posterior rami

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[EParker37]

Some more detail would be helpful, I am not quite sure I understand the question. There are both anterior and posterior portions of the brachial plexus for instance.

 

[cometstarg]

Some more detail would be helpful, I am not quite sure I understand the question. There are both anterior and posterior portions of the brachial plexus for instance.

Unless I'm mistaken, the brachial plexus typically arises from the C5-T1 ventral rami.

 

[EParker37]

Unless I'm mistaken, the brachial plexus typically arises from the C5-T1 ventral rami.

Yes, it does, I was referring to the anterior posterior divisions of the plexus, I was mainly fishing for more information, as this question doesn't seem to make a lot of sense.

 

[M.shehab]

The Cervical plexus is formed by the (ventral rami) of the upper four cervical nerves and the upper part of fifth cervical ventral ramus

The Brachial plexus is formed by the (ventral rami )of C5-C8-T1 spinal nerves, and lower and upper halves of C4 and T2 spinal nerves.

Lumbar plexus :from The (ventral rami) of L1-L5 spinal nerves with a contribution of T12

Sacral plexus: from (Ventral rami) of L4-S3 with parts of L4 and S4 spinal nerves

So,why every plexus emerge from ventral rami of spinal nerve not from dorsal rami?

 

[EParker37]

My guess is that it is due to the fact that the nerves originating from the dorsal ramus innervate the deep muscles of the back, while the nerves coming out of the ventral ramus innervate everything anterior from the spine.

 

[M.shehab]

Thank you

 

[Labrat07]

Hmm, I don't know anything about this. Is there a topic for this on MCAT outline?