what CN innervates the Platysma?

[kapMD/PhD]

Ok - this is an ongoing debate between me and a professor of mine. Without looking- can you tell me which CN you think innervates the platysma. (you can look if you must- you migth be surprised)

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[Solideliquid]

Ok - this is an ongoing debate between me and a professor of mine. Without looking- can you tell me which CN you think innervates the platysma. (you can look if you must- you migth be surprised)

Well without looking my initial reaction is CN IX?


EDIT- oh OK its CNVII.

 

[kcumbDO]

cervical branch of the facial nerve

 

[kapMD/PhD]

It seems that there is a widespread misconception and thought that the platysma is innervated by CN XI; but it is in fact innervated by the cervical branch of CN 7, as it is included as a muscle of facial expression and is derived from the 2nd branchial arch! GO YOU!

 

[undecided3yr]

It seems that there is a widespread misconception and thought that the platysma is innervated by CN XI; but it is in fact innervated by the cervical branch of CN 7, as it is included as a muscle of facial expression and is derived from the 2nd branchial arch! GO YOU!

Why would you think a ocular muscle nerve would be connected to the neck?

 

[kapMD/PhD]

I'm not sure what you mean when you say an "ocular muscle nerve." As far as i know the muscles of the eye are CN 3,4,6. the eye closure is partly controlled by 7, but there are many other muscles of the face that are also controlled by 7 (think Bells palsy and central 7). THere are 5 branches of the 7th cranial nerve's branchial motor component: temporal, zygomastic, buccal, mandibular, and cervical. The cerrvical branch innervates the platysma becasue of it's embryological origins. Hope this helps- let me know if i was confused as to your comment.

 

[undecided3yr]

oops when I first glanced at the thread, I thought the post had been VI, now that I look again, I see that it was XI. I still dont see how innervation of the platysma could be confused with XI or even IX as I saw posted in some of the responses.

I was agreeing that it was the cervical division of VII.

 

[LanceArmstrong]

Ok - this is an ongoing debate between me and a professor of mine. Without looking- can you tell me which CN you think innervates the platysma. (you can look if you must- you migth be surprised)

Obviously the facial nerve. The spinal accessory inervates the SCM. Here's a question - what nerves provides the sensations over the platysma?

 

[psychbender]

Obviously the facial nerve. The spinal accessory inervates the SCM. Here's a question - what nerves provides the sensations over the platysma?

Anterior rami of C3/4 and CN VII (cervical and mandibular branches)?

 

[Nerdoscience]

Transverse cervical n. (C2, C3)

 

[Nerdoscience]

Obviously the facial nerve. The spinal accessory inervates the SCM. Here's a question - what nerves provides the sensations over the platysma?

The spinal accessory nerve also innervates the trapezius. Of note, the spinal accessory nerve is only kind of a cranial nerve. It has no nerve roots in the brain; the nerve roots from the accessory nucleus actually are part of the CN X (Clinical Anatomy 15:4-10, 2002).

 

[neurodoc]

The platysma is innervated by CN VII. There is a test for facial nerve palsy, the "other Babinski sign." Ask your patient to grimace, tensing his platysma muscles. The platysma will be weak on the side of the LMN facial weakness. This is the so-called "facial Babinski sign."

 

[Nerdoscience]

The platysma is innervated by CN VII. There is a test for facial nerve palsy, the "other Babinski sign." Ask your patient to grimace, tensing his platysma muscles. The platysma will be weak on the side of the LMN facial weakness. This is the so-called "facial Babinski sign."

I thought the "other" Babinski sign was about the upper face relating to frontalis activation with closure of the eye in facial hemispasm.