Pharyngeal pouch (embryology) 3519753 218717443 2008-06-11T21:25:06Z 79.112.40.66 {{Infobox Embryology | Name = {{PAGENAME}} | Latin = | GraySubject = 13 | GrayPage = 65 | Image = Kiemenbogen.jpg | Caption = Pattern of the branchial arches. I-IV branchial arches, 1-4 [[branchial pouches]] (inside) and/or [[pharyngeal grooves]] (outside)<BR>a [[Tuberculum laterale]]<BR>b [[Tuberculum impar]]<BR>c [[Foramen cecum]]<BR>d [[Ductus thyreoglossus]]<BR>e [[Sinus cervicalis]] | Image2 = Gray979.png | Caption2 = Floor of pharynx of human embryo about twenty-six days old. | System = | CarnegieStage = 10 | Precursor = | GivesRiseTo = | MeshName = | MeshNumber = | DorlandsPre = p_31 | DorlandsSuf = 12662655 | }} In the [[Embryogenesis|development]] of [[Vertebrate|vertebrate animals]], '''Pharyngeal''' or '''branchial pouches''' form on the endodermal side between the [[branchial arch]]es, and pharyngeal grooves (or clefts) form the lateral ectodermal surface of the neck region to separate the arches. The pouches line up with the clefts, and these thin segments become [[gills]] in [[fish]]. == The pouches == ===First pouch=== This is the only pouch in which the endoderm and ectoderm remain close together, as the [[tympanic membrane]]. There is minimal mesoderm in the tympanic membrane. *The [[endoderm]] lines the future [[auditory tube]], [[middle ear]], [[mastoid antrum]], and inner layer of the tympanic membrane. *The [[ectoderm]] lines the future [[external acoustic meatus]] and outer layer of the tympanic membrane. *[[Mesoderm ]] remains as the middle portion of the tympanic membrane, where the endoderm of the first pharyngeal pouch and the ectoderm of the first pharyngeal cleft have met. ===Second pouch=== *Contributes to the [[middle ear]], [[tonsils]], supplied by the [[facial nerve]]. ===Third pouch=== *The third pouch possesses Dorsal and Ventral wings. Derivatives of Dorsal include the inferior [[parathyroid gland]]s, while the ventral wings fuse to form the cytoreticular cells of the [[thymus]]. The main nerve supply to the derivatives of this pouch is Cranial Nerve IX, glossopharyngeal nerve. ===Fourth pouch=== *Derivatives include the superior [[parathyroid gland]] and [[parafollicular]] C-Cells of the [[thyroid gland]]. ===Fifth pouch=== *[[Rudimentary]] structure, becomes part of the fourth pouch contributing to thyroid C-cells.<ref>[http://www.mc.vanderbilt.edu/histology/labmanual2002/labsection3/ThyroidParathyroidIslets03.htm Endocrine Glands<!-- Bot generated title -->]</ref> ==See also== * [[branchial arch]] * [[DiGeorge syndrome]] ==References== {{reflist}} ==External links== * {{EmbryologySwiss|rrespiratory/korperhohlen01}} (Item #1 at Fig. 14) * {{EmbryologyTemple|parch98/ARCHII97/sld017}} * {{EmbryologyUNC|hednk|021}} * {{EmbryologyUNC|hednk|022}} * [http://www.med.howard.edu/anatomy/gas/wk7/Lecture%2024.htm Outline at howard.edu (scroll down to "III. THE PHARYNGEAL POUCHES")] {{Embryology of head and neck}} [[Category:Animal anatomy]] [[Category:Developmental biology]] [[Category:Embryology]] [[Category:Head and neck]] [[pl:Kieszonki skrzelowe]]