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In the embryonic development of vertebrates, pharyngeal pouches form on the endodermal side between the pharyngeal arches. The pharyngeal grooves (or clefts) form the lateral ectodermal surface of the neck region to separate the arches.
Pharyngeal pouches form on the endodermal side between the arches, and pharyngeal grooves (or clefts) form from the lateral ectodermal surface of the neck region to separate the arches. [8] In fish, the pouches line up with the clefts, and these thin segments become gills.
A pharyngeal groove (or branchial groove, or pharyngeal cleft [1]) is made up of ectoderm unlike its counterpart the pharyngeal pouch on the endodermal side. The first pharyngeal groove produces the external auditory meatus (ear canal). [ 2 ]
Pharyngeal pouches develop into future parts in face and head. The pouches penetrate the surrounding mesenchyme but do not establish communication with the pharyngeal grooves. They appear simultaneously with the development of the arches. [7] The first pharyngeal pouch is characterized by narrowing at its final segment.
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)
However, it is now accepted [who?] that it is the vertebrate pharyngeal pouches and not the neck slits that are homologous to the pharyngeal slits of invertebrate chordates. [citation needed] Pharyngeal arches, pouches, and clefts are, at some stage of life, found in all chordates. One theory of their origin is the fusion of nephridia which ...
3.2 Pharyngeal pouch. 3.3 Hindgut/cloaca. 4 See also. 5 References. Toggle the table of contents. List of human cell types derived from the germ layers. 10 languages.
The cervical sinus is bounded in front by the second pharyngeal arch (hyoid arch), and behind by the thoracic wall. The second pharyngeal arch (hyoid arch) grows faster than the other pharyngeal arches, so they become covered. It is ultimately obliterated by the fusion of its walls by the 7th week of gestation.