Simple question about a dermatome?

[sameeralord]

Hello everyone,

I have a quick question, let's say there is a L1 dermatome, which is a large area. Now my question is does L1 nerve divide into many branches to supply this area, also do these branches carry only sensory nerves?

Thanks

 

[bobze]

Hello everyone,

I have a quick question, let's say there is a L1 dermatome, which is a large area. Now my question is does L1 nerve divide into many branches to supply this area, also do these branches carry only sensory nerves?

Thanks

Yes it divides, after the spinal nerve, these split off as lateral and medial (and more) branches.

Spinal nerves carry both afferent and efferent neurons.

 

[sameeralord]

Yes it divides, after the spinal nerve, these split off as lateral and medial (and more) branches.

Spinal nerves carry both afferent and efferent neurons.

Thanks that's what I was thinking. Yes spinal nerves have both afferent and efferent, but the nerve branch supplying the dermatome does it only have sensory nerves?

 

[bobze]

Thanks that's what I was thinking. Yes spinal nerves have both afferent and efferent, but the nerve branch supplying the dermatome does it only have sensory nerves?

Sorry I was tired when I wrote that and didn't understand your question. Yes a dermatome is specifically from dorsal roots, so sensory only. Traveling with these is sympathetic fibers for innervation of involuntary muscles of the dermatome, like arrector pili.

The myotome mapping corresponds to the efferent parts of the spinal nerve after the split which let's you move voluntary (skeletal) muscle.