Transcript 201 L.3Coelomic Cavities

Embryology of the Gut
and Lungs
212 Functional Anatomy
Stuart 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 reenters abdomen
 Omphalocele....no re-entry
 Umbilical hernia, goes back out covered
in peritoneum
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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
Front
Dorsal
Mesentary
Ventral
Mesentary
Back
Splenic
tissue
Epiploic
Foramen
Omentum
Liver and spleen form in mesentary
Anterior
1. Falciform ligament
1
2. Lesser Omentum
Liver
2
Stomach
3 4a
4b
Posterior
Spleen
3. Dorsal mesentary, divided into:4a. Gastrosplenic ligament
4b. Lienorenal ligament
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)
Blood Supply to
Abdominal
Organs
 Celiac trunk

Foregut
 Midgut
 Superior mesenteric
artery

Hindgut
 Inferior mesenteric
artery

Rectum
 Internal iliac artery
(pudendal and rectal
arteries)
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 cell
Mesenteries are important:
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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