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The first pharyngeal arch, also mandibular arch (corresponding to the first branchial arch of fish), is the first of six pharyngeal arches that develops during the fourth week of development. [10] It is located between the stomodeum and the first pharyngeal groove .
The first and second arches disappear early. A remnant of the 1st arch forms part of the maxillary artery, [3] a branch of the external carotid artery. The ventral end of the second develops into the ascending pharyngeal artery, and its dorsal end gives origin to the stapedial artery, [3] a vessel which typically atrophies in humans [4] [5] but persists in some mammals.
Pattern of the pharyngeal arches. I-IV pharyngeal arches, 1–4 pharyngeal pouches (inside) and/or pharyngeal grooves (outside) a Tuberculum laterale b Tuberculum impar c Foramen cecum d Ductus thyreoglossus e Sinus cervicalis. The pharyngeal apparatus is an embryological structure. [1] [2] It consists of: pharyngeal grooves (from ectoderm ...
The epithelium of the larynx is of endodermal origin, but the laryngeal cartilages, unlike the rest of the respiratory bud connective tissue, come from the mesenchyme of the fourth and sixth pharyngeal arches. The fourth pharyngeal arch, adjacent to what will be the root of the tongue, will become the epiglottis.
Derivatives include: superior parathyroid glands and ultimobranchial body which forms the parafollicular C-Cells of the thyroid gland. Musculature and cartilage of larynx (along with the sixth pharyngeal arch). Nerve supplying these derivatives is Superior laryngeal nerve.
In humans, the ultimopharyngeal body is an embryological structure, and is a derivative of the ventral recess of the fourth pharyngeal pouch. [1] [2] It is technically from the fifth pharyngeal pouch, but this is rudimentary and merges with the fourth. [2] It develops into the parafollicular cells of the thyroid. [2]
Parafollicular cells are derived from pharyngeal endoderm. [2] [3] Embryologically, they associate with the ultimopharyngeal body, which is a ventral derivative of the fourth (or fifth) pharyngeal pouch. Parafollicular cells were previously believed to be derived from the neural crest based on a series of experiments in quail-chick chimeras.
The gill arches form as pharyngeal arches during embryogenesis, and lay the basis of essential structures such as jaws, the thyroid gland, the larynx, the columella (corresponding to the stapes in mammals) and in mammals, the malleus and incus. [2] Studies on placoderms also show that the shoulder girdle also originated from gill arches. [6]