Embryology of the Gut and Lungs 212 Functional Anatomy Stuart Bunt
Feb 22, 2016
Embryology of the Gut and Lungs
212 Functional AnatomyStuart Bunt
Embryonic Curvature traps part of the yolk sac inside the embryo to form the gut.
Embryology of Gut
Lung Buds from the Gut
Stages of Lung Development
Physiological hernia The large liver takes up abdominal space
Intestine lengthens into umbilicus
Rotates as it grows out and again as it re-enters abdomen Omphalocele....no re-entry Umbilical hernia, goes back out covered
in peritoneum
Complex adult layout due to 270o rotation Foregut, Midgut and Hindgut suspended by the dorsal
mesentary, initially straight Ventral mesentary connects stomach and ant. abd. wall, rest
of gut free anteriorly Mesentary supplies blood and nerves to gut between layers of
peritoneum
Stomach rotates and distends
FrontFront
BackBack
OmentumOmentum
Dorsal Dorsal MesentaryMesentary
VentralVentralMesentaryMesentary
Splenic Splenic tissuetissue
Epiploic Epiploic ForamenForamen
Liver and spleen form in mesentary
LiverLiver
SpleenSpleen
StomachStomach
11
22
4a4a4b4b
1. Falciform ligament1. Falciform ligament
2. Lesser Omentum2. Lesser Omentum
3. Dorsal mesentary, divided into:-3. Dorsal mesentary, divided into:-
4a. Gastrosplenic ligament4a. Gastrosplenic ligament
4b. Lienorenal ligament4b. Lienorenal ligament33
AnteriorAnterior
PosteriorPosterior
Formation of Omentum
90 degrees rotation
180 degrees rotation
Final 90 - 270 degrees in total
Blood Supply of the Gut Celiac trunk
Foregut Midgut
Superior mesenteric artery
Hindgut Inferior mesenteric
artery Rectum
Internal iliac artery (pudendal and rectal arteries)
Celiac trunk Foregut Midgut
Superior mesenteric artery
Hindgut Inferior mesenteric artery
Rectum Internal iliac artery
(pudendal and rectal arteries)
Blood Supply to Abdominal
Organs
Canalisation of the Gut
Peritoneum
Flattened endothelial cells on fibro-elastic connective tissue
Parietal and visceral layers Makes gut watertight Suspends gut Contains nerves and blood vessels Omentum contains infection
Flattened Endothelial cellFlattened Endothelial cell
Mesenteries are important:-
Paracolic gutters channel fuid
Stop herniation due to bipedal posture
Supply blood/nerves Sensitive to stretch Contain infection Useful in surgery
Intra and Retroperitoneal
To prevent the intestines falling into the pelvis our upright posture has been accompanied by a fusion of parts of the gut tube to the posterior abdominal wall. These parts become retro-peritoneal.
Uro-rectal septum divides the bladder and urogenital sinus from the rectum