Gastrointestinal Tract - Carnegie Stage 22
Stage 22 Embryo
The individual serial slices have also been incorporated into a 3D model of this embryo.
|E6L||Liver. Ductus venosus.
Cardio-oesophageal junction (cf. E5).
Inferior vena cava.
|E7L||Stomach body, with mucosa, submucosa and muscularis externa.
Lesser sac. Lesser omentum. Pyloroduodenal junction. Folded duodenal mucosa.
Inferior vena cava. Portal vein. Hepatic ducts. Gallbladder.
|F1L||Stomach body. Spleen. Pyloric canal. Duodenum.
Small intestine loop (jejunum) cut tangentially, ventral to liver.
|F2L||Stomach, spleen. Superior mesenteric artery.
Superior mesenteric vein crossing cranial to body of pancreas.
Tail of pancreas.
Small intestinal loop herniating from abdominal cavity into the coelom of the umbilical cord (remnant of extra-embryonic coelom).
|F4L||Greater curvature of stomach (tangential section). Lesser sac. Greater omentum. Duodenal/jejunal junction.
Note colon (small lumen, darkly-staining wall) and its mesocolon.
Note the sections of small and large intestine within the umbilical cord coelom and their mesenteries.
Note the thickened jelly to one side of the umbilical cord, containing umbilical vein and R umbilical artery.
|F5L||Lesser sac. Greater omentum. Duodenum. Jejunum (cut twice with mesentery in between). Colon and mesocolon.|
|F6L||Greater omentum and lesser sac.
Jejunum with mesentery.
Colon with mesocolon.
Three layers of abdominal muscles.
Both umbilical arteries now inside abdominal cavity with urachus between them.
|F7L||In abdominal cavity - colon with mesocolon, jejunum. Greater omentum and lesser sac.
Umbilical cord - containing umbilical arteries and small dark allantois. Umbilical cord coelom containing mainly, small intestinal loops with their mesentery.
||Umbilical cord and coelom containing small intestine loops.
Colon and mesocolon. Jejunum (G1 only).
Bladder with umbilical arteries either side.
Umbilical arteries arising from common iliac arteries.
|G5L||Recto-anal junction with rectovesical pouch of peritoneal cavity.|
|G6L||Anal canal with triangular lumen.|