Somitomere 1557084 164622765 2007-10-15T01:35:23Z Arcadian 104523 outline {{Infobox Embryology | Name = {{PAGENAME}} | Latin = | GraySubject = | GrayPage = | Image = | Caption = | Image2 = | Caption2 = | System = | CarnegieStage = 11 | Days = third [[gestation]]al week | Precursor = [[paraxial mesoderm]] | GivesRiseTo = [[somites]] | MeshName = | MeshNumber = | DorlandsPre = | DorlandsSuf = | }} In the developing [[vertebrate]] [[embryo]], the '''somitomeres''' are loose masses of [[paraxial mesoderm]] derived [[cell (biology)|cells]] that form along each side of the [[neural tube]] towards the end of the third [[gestation]]al week. The approximately 50 pairs of somitomeres begin developing in the cranial (head) region, continuing in a caudal (tail) direction until the end of week four. ==Development== The first seven somitomeres give rise to the striated muscles of the [[face]], [[jaw]]s, and [[throat]]. The remaining somitomeres, likely driven by periodic expression of the ''[[hairy (gene)|hairy]]'' gene, begin expressing adhesion proteins such as [[cadherin|N-cadherin]] and [[fibronectin]], compact, and bud off forming [[somite]]s. The somites give rise to the [[vertebral column]] ([[sclerotome]]), associated muscles ([[myotome]]), and overlying dermis ([[dermatome]]). ==External links== * {{EmbryologySwiss|hdisqueembry/triderm07}} - look for Fig. 16 [[Category:Embryology]] {{developmental-biology-stub}} {{Embryology}}