- Stomodeum
Infobox Embryology
Name = PAGENAME
Latin =
GraySubject = 241
GrayPage = 1101
Caption = Human embryo about fifteen days old.Brain andheart represented from right side.Digestive tube andyolk sac in median section. (Stomodeum labeled in upper right.)
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CarnegieStage = 9
Precursor =surface ectoderm
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DorlandsPre = s_24
DorlandsSuf = 12760230The stomodeum, also called stomatodeum, is a depression between the
brain and thepericardium in anembryo , and is the precursor of themouth and the anterior lobe of thepituitary gland .tructure
The stomodeum is lined by
ectoderm , and is separated from the anterior end of thefore-gut by the buccopharyngeal membrane.This membrane is devoid of
mesoderm , being formed by the apposition of the stomodeal ectoderm with the fore-gut endoderm; at the end of the third week it disappears, and thus a communication is established between the mouth and the futurepharynx .Development
The mouth is developed partly from the stomodeum, and partly from the floor of the anterior portion of the
fore-gut .By the growth of the head end of the
embryo , and the formation of thecephalic flexure , thepericardial area and thebuccopharyngeal membrane come to lie on the ventral surface of theembryo .With the further expansion of the
brain , and the forward bulging of thepericardium , the buccopharyngeal membrane is depressed between these two prominences. This depression constitutes the stomodeum.No trace of the membrane is found in the adult; and the communication just mentioned must not be confused with the permanent isthmus faucium.
The
lips ,teeth , andgums are formed from the walls of the stomodeum, but thetongue is developed in the floor of the pharynx.
=AdditionalExternal links
* [http://connection.lww.com/Products/sadler/images/figurelarge15-5.jpgDiagram at lww.com]
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