BGDB Gastrointestinal - Early Embryo: Difference between revisions

From Embryology
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| [[File:Gray0982a.jpg|The early developing gastrointestinal tract]]
| [[File:Gray0982a.jpg|The early developing gastrointestinal tract]]
| [[File:Gray0982b.jpg|The later developing gastrointestinal tract]]
| [[File:Gray0982b.jpg|The later developing gastrointestinal tract]]
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| Early Embryo
| Later Embryo
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Revision as of 17:10, 14 April 2011

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Practical 1: Trilaminar Embryo | Early Embryo | Late Embryo | Fetal | Postnatal | Abnormalities | Lecture | Quiz


We have now reached the end of Week 4 and beginning of 5 of development. Start by looking briefly at the overview of the Carnegie stage 13 embryo GIT from one end to the other.

Then work through the listed specific serial sections of the embryo identifying the GIT features. Alternatively step through the serial sections yourself identifying the tract, its associated mesentries, organs and spaces.

Tract Development

The early developing gastrointestinal tract The later developing gastrointestinal tract
Early Embryo Later Embryo

Peritoneal Cavity

Stomach Development

The stomach initially appears at this stage (5 weeks) as a dilatation of the GIT in the foregut, which over the next 2 weeks will continue to expand to a fusiform structure and differential growth will it rotate in both the longitudinal and the horizontal planes.

Differential growth of the ventral and dorsal stomach walls leads to establishing a lesser and greater curvature.

(Quicktime movie in new window)

(Animation based upon images from Human Embryology, Larsen)

Key: Yellow - endoderm of stomach. Red - mesentry (ventral at front and dorsal at back). The dorsal mesogastrium will form the greater omentum and the ventral mesogastrium will form the lesser omentum. Blue - vagus nerve branches (left and right). A 90 degree rotation (during week 7) brings the left vagus anteriorly (to the front) and carries the right vagus posteriorly (to the back).

These combined rotations position the stomach in its adult orientation and movement of the mesenteries also moves the developing liver to the right and generates the greater omentum and lesser sac (see animations below).

Lesser Sac Development

(Quicktime movie in new window)

(Animation based upon images from Human Embryology, Larsen)

Key: Yellow - endoderm of stomach. Orange - liver developing in ventral mesogastrium. Red - spleen developing in dorsal mesogastrium.

Development of Lesser Sac and Greater Omentum

(Quicktime movie in new window)

(Animation based upon images from Human Embryology, Larsen)


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Cite this page: Hill, M.A. (2024, March 28) Embryology BGDB Gastrointestinal - Early Embryo. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/BGDB_Gastrointestinal_-_Early_Embryo

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© Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G