Gastrointestinal Tract - Stomach Development
Introduction
This section of notes gives an overview of how the stomach and duodenum develops. The GIT is best imagined as a simple tube, the upper part being the foregut diverticulum, which is further divided into oesophagus and stomach.
During week 4 at the level where the stomach will form the tube begins to dilate, forming an enlarged lumen. The dorsal border grows more rapidly than ventral, which establishes the greater curvature of the stomach. A second rotation (of 90 degrees) occurs on the longitudinal axis establishing the adult orientation of the stomach.
Some Recent Findings
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Components of Stomach Formation
primitive endoderm
- foregut diverticulum (pocket)
- pharyngeal region of foregut
- laryngo-tracheal groove (see respiratory tract)
- oesophageal region of foregut
- oesophagus
- stomach
- glandular/proventricular/pyloric stenosis
- fundus/pyloric antrum
- pyloric sphincter
- fundus/pyloric antrum
- dorsal mesogastrium
- lieno-renal ligament
- splenic primordium
- spleen
- gastro-splenic ligament
- duodenum (rostral half)
- splenic primordium
- lieno-renal ligament
- glandular/proventricular/pyloric stenosis
- stomach
- oesophagus
- pharyngeal region of foregut
- foregut-midgut junction
- midgut region
- hindgut diverticulum (pocket)
Modified from [2]
Stage 13
The images below link to larger cross-sections of the mid-embryonic period (end week 4) stage 13 embryo starting just above the level of the stomach and then in sequence through the stomach to the level of the duodenum.
D1L | D2L | D3L | D4L | D5L | D6L | D7L |
This is an animation based on a reconstruction of the above embryo entire stage 13 gastrointestinal tract. |
- Links: Carnegie stage 13 - serial sections | Embryo Serial Sections | Flash movies | Quicktime movies
Stage 22
E5L | E6L | E7L | ||
F1L | F2L | F3L | F4L | F5L |
This is an animation based on a reconstruction of the above embryo entire stage 22 gastrointestinal tract. |
- Links: Carnegie stage 22 - serial sections | Embryo Serial Sections | Flash movies | Quicktime movies
Greater Omentum
The greater omentum hangs like an apron over the small intestine and transverse colon. It begins attacted to the inferior end of the stomach as a fold of the dorsal mesogastrium which later fuses to form the structure we recognise anatomically. The figure below shows a lateral view of this process comparing the early second trimester arrangement with the newborn structure. |
Duodenum/Pancreas Rotation
After the stomach the initial portion of the gastrointestinal tract tube is the duodenum which initially lies in the midline within the peritoneal cavity.
This region, along with the attached pancreas, undergoes rotation to become a retroperitoneal structure. This diagram shows the rotation with spinal cord at the top, vertebral body then dorsal aorta then pertioneal wall and cavity. |
Stomach Hormonal Development
The gastrointestinal tract has its own complex entero-endocrine system (enterohormones) that regulates many regional tract functions.
Cells within the stomach express a range of peptide hormones known to regulate a range of gastric functions including secretion of digestive enzymes, mucous and the movement of the luminal contents. The list below shows the earliest detectible presence of specific hormone-containing cells in regions of the developing human stomach.
Hormonal Timecourse
8 weeks - Gastrin containing cells in stomach antrum. Somatostatin cells in both the antrum and the fundus.
10 weeks - Glucagon containing cells in stomach fundus.
11 weeks - Serotonin containing cells in both the antrum and the fundus.
Expression data based upon[3]
Other Gut Peptides
- Cholecystokinin (CCK), pancreatic polypeptide, peptide YY, glucagon-like peptide-1 (GLP-1), oxyntomodulin (increase satiety and decrease food intake) and ghrelin
References
Search Pubmed
Search Bookshelf: Stomach Development
Search Pubmed Now: Stomach Development
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Cite this page: Hill, M.A. (2024, June 18) Embryology Gastrointestinal Tract - Stomach Development. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Gastrointestinal_Tract_-_Stomach_Development
- © Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G