Talk:Pharyngeal arch

Fourth arch and sixth arch distinctions

The levator veli palatini is innervated by the vagus nerve. Since the vagus nerve and its branch, the superior laryngeal nerve, arise from the 4th pharyngeal arch, it must have arisen from the same arch in order to be innervated by this specific nerve. The cricothyroid is innervated by a branch of the vagus, the superior laryngeal. The superior laryngeal branches into the interior and external laryngeal. The internal provides sensory innervation to the mucosa above vocal folds, while the external has the distinction of innervating a muscle--cricothyroid. This is also the only muscle that tenses the vocal cords. All of these nerves have their origin in Arch 4.

On the other hand, Arch 6 gives rise to the recurrent laryngeal which travels with vagus once the cells go motile (stop expressing cadherins and other anchoring proteins). Then loops up (recurrent) to lay down the other muscles that modulate the laryngeal apparatus. It also forms the laryngeal cartilages. It innervates the other intrinsic muscles of the larynx and the mucosa below the vocal folds.

I'm pulling from Developmental anatomy and Anatomy notes. UT Houston Med School. Appreciate comments.

The fifth pouch

Kaplan Qbank for USMLE Step-1 states that parafollicular C-cells develop from the fifth pouch. The other sources I saw (including this page) say they are from the fourth. It is probably some kind of historical confusion. Maybe they are really from the fifth, but since it fuses with the fourth we can consider that they are now from the fourth indeed. I wonder what would be the right way to reflect this on the page. Thanks! Skovorodkin 23:13, 19 June 2006 (UTC)

My understanding is that the ultimobranchial body develops from the ventral portion of the fifth pouch. This is confirmed by indiana.edu, for what it's worth [1].--David Iberri (talk) 22:23, 10 November 2006 (UTC)

Just to add that current med school is teaching 4th arch. Having taught Kaplan MCAT they have some poor info. —Preceding unsigned comment added by 129.106.122.117 (talk) 04:38, 17 October 2009 (UTC)

Trapezius and sternocleidomastoid

My lecturers taught us that trapezius and sternocleidomastoid came from the 6th arch. The only anatomy book that I have at my disposal at the moment, Netter's Head and Neck Anatomy for Dentistry by Neil S. Norton, does not list them as such, and neither does this page. Of course I'll continue to write them as coming from the 6th arch in exams, but I'm just curious if someone can confirm or deny this. 123.2.211.122 (talk) 15:29, 28 March 2010 (UTC)

It is true that the trapezius and sternocleidomastoid muscles arise from the 6th pharyngeal arch, and these muscles receive motor innervation via the XI Cranial Nerve(Spinal Accessory Nerve). Textbook: Oral Development and Histology - 3rd Edition - James K. Avery Publisher- Thieme (Stuttgart,NewYork) 115.184.36.152 (talk) 12:31, 30 December 2011 (UTC)Dr. Kunal

Mergers

The following discussion is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

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Proposed merge with Branchiomeric musculature

Clear duplication Tom (LT) (talk) 23:31, 30 September 2014 (UTC)

Proposed merge with Second pharyngeal arch

Unneccessary fragmentation. Would be better presented with parent article. Can be reexpanded later if needed. Tom (LT) (talk) 23:31, 30 September 2014 (UTC)

Proposed merge with First pharyngeal arch

See above reasoning. Having all this information in one article will help readers and enhance the readability, comprehensiveness and quality of the article. Tom (LT) (talk) 23:32, 30 September 2014 (UTC)

Agree. Most of the content in the article isn't about the arch by itself but a collection of summaries of other articles (see First pharyngeal arch#Meckel's cartilage for a clear example). They can be merged readily without loss of content. --Tilifa Ocaufa (talk) 06:00, 14 February 2015 (UTC)

 Done --Tom (LT) (talk) 02:42, 8 March 2016 (UTC)

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.