Step I First Aid Embryology mistake

[Pathinterpreter]

2007 FA page 122 says laryngeal cartilages derive from neural crest, but in page 126 says that laryngeal cartilages (thyroid, cricoid, arytenoids, corniculate, cuneiform) derive from 4th and 6th branchial arches.
Wich one is correct? [Langman says they are from 4th and 6th branchial arches].

Thank you



The best runner is the one that ignores being in a race

 

[rme04]

there is a several page addendum of corrections to that version of First Aid. i dont have it on hand, but im sure you can google it.

 

[AmyO]

I'm not studying for the USMLE yet (just started 2nd yr), but we just covered this in class and I just looked at these notes tonight. Technically, they're both right. The skeletal element that develops in the 4th & 6th pharyngeal/branchial arches is all of the laryngeal cartilage (thyroid, arytenoid, corniculate, cuneiform & cricoid) except the epiglottis. All of the skeletal elements from all of the pharyngeal arches is formed by neural crest cells that have migrated into this region. Hope this makes sense! Good luck!