1. Embryology of the Gut and Lungs
212 Functional Anatomy
Stuart Bunt

2. Embryonic Curvature traps part of the yolk sac inside the embryo to form the gut.

3. Embryology of Gut

4. Lung Buds from the Gut

5. Stages of Lung Development

6. 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

7. 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

8. Stomach rotates and distends
Front
Dorsal
Mesentary
Ventral
Mesentary
Back
Splenic
tissue
Omentum
Epiploic
Foramen

9. Liver and spleen form in mesentary
Anterior
1. Falciform ligament
2. Lesser Omentum
3. Dorsal mesentary, divided into:-
4a. Gastrosplenic ligament
4b. Lienorenal ligament 1
Liver 2
Stomach 4a
Spleen 3 4b
Posterior

10. Formation of Omentum

11. 90 degrees rotation

12. 180 degrees rotation

13. Final 90 - 270 degrees in total

14. Blood Supply of the Gut Foregut Midgut Hindgut Rectum Celiac trunk
Superior mesenteric artery
Hindgut
Inferior mesenteric artery
Rectum
Internal iliac artery (pudendal and rectal arteries)

15. Blood Supply to Abdominal Organs
Celiac trunk
Foregut
Midgut
Superior mesenteric artery
Hindgut
Inferior mesenteric artery
Rectum
Internal iliac artery (pudendal and rectal arteries)

16. Canalisation of the Gut

17. 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

18. Mesenteries are important:-
Paracolic gutters channel fuid
Stop herniation due to bipedal posture
Supply blood/nerves
Sensitive to stretch
Contain infection
Useful in surgery

19. 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.

21. Uro-rectal septum divides the bladder and urogenital sinus from the rectum