1. Development of digestive system and respiratory system
Primitive gut
Development of primary pharynx
Development of esophagus and stomach
Intestinal development
Development of liver, gall bladder and pancreas
Development of larynx, trachea and lung

2. Primitive gut Primitive gut ：3rd～4th week Endoderm→ primitive gut
buccopharyngeal membrane (breach at 4th week)
→ cloacal membrane (breach at 8th week)
foregut, midgut and hindgut
Vitelline stalk (atresia at 6th week)

3. Vitelline stalk
Foregut
Midgut
Hindgut
Allantois

4. Foregut
Hindgut

5. Development of primary pharynx
Primary pharynx：flattened funnel
Pharyngeal pouch：5 pairs
First： branchial membrane →tympanic membrane
outer portion →tympanic cavity
inner portion →pharyngotympanic tube

6. Second：outer portion → degeneration Third：ventral portion →thymus
inner portion →tonsil
Third：ventral portion →thymus
dorsal portion → inferior parathyroid gland
Fourth：ventral portion →degeneration
dorsal portion → superior parathyroid gland
Fifth：ultimobranchial body →parafollicular cell

7. 1 2 3 4 5

8. External acoustic meatus
pharyngotympanic tube
tympanic cavity
tympanic membrane
External acoustic meatus
thyroid
Palatine tonsil
superior parathyroid gland
inferior parathyroid gland
thymus

9. Development of esophagus and stomach
1. Esophagus：primitive gut
between laryngotracheal diverticulum
and stomach
2. Stomatch：a dilation at the end of foregut

10. Development of esophagus
①prolong
②simple → stratified
③reconstitution of lumen

11. Development of stomach
a dilation at the end of foregut

12. Dorsal convex left
Ventral concave right

13. Dorsal mesogastrium
Ventral mesogastrium
Left
Right

14. Head
Liver
Duodenum
End

15. Intestinal development
1. Evolvement of midgut
① Midgut loop：
5th week
② Physiological umblical herniation:
6th week
③ Counter-clockwise 90°rotation, caecal swelling
6th to 8th week
④ Counter-clockwise 180°rotation
10th week

17. A B C D

18. 2. Evolvement of hindgut
Compartmentation of cloaca:
urorectal septum (6-7th week)
Anorectal canal (dorsal)
Cloaca
Urogenital sinus (ventral)
Anal membrane (dorsal)
Cloacal membrane
Urogenital membrane
(ventral)

19. Urorectal septum
Urogenital sinus
Urogenital membrane
Anal membrane
Anorectal canal

20. Development of liver, gall bladder and pancreas
Time
4th week
Process
Head
Hepatic cord
Stroma,
Capsule
Hepatic diverticulum
End of foregut
Mesenchyme
Tail
Gall bladder

21. Hepatic cord → Hepatic plate
Vitelline vein and umbilical vein →Hepatic sinusoid
Bile canaliculus: 6th week
Hematopoietic stem cell: 6th week
Hepatic lobule : 9-10th week

22. 2. Development of pancreas
Above of hepatic diverticulum
4th week
Fusion
Dorsal parentic bud
Dorsal
pancreas
Left
Pancreas
End of foregut
Rotation
Ventral parentic bud
Ventral pancreas
Right
Under hepatic diverticulum

23. 但怪但 Head of hepatic diverticulum Dorsal pancreatic bud
End of hepatic diverticulum
但怪但
Ventral pancreatic bud

24. 碱
Liver
Dorsal pancreas
Gall bladder
Ventral pancreas

25. Dorsal pancreas
Ventral pancreas

26. Pancreas islet: function from 5th month
Main pancreatic
duct
Ventral pancreas
Dorsal pancreas
Accessory
pancreatic duct
Duodenum
Pancreas islet: function from 5th month

27. Abnormality of digestive system
1.Meckel’s diverticulum
2. Umbilical fistula　

28. ３.Congenital umbilical hernia

29. 4. Imperforate anus
Rectum
Anal pit
Atresia

30. 5.Congenital megacolon

31. Laryngotracheal groove
Development of larynx, trachea and lung
4th week
Laryngotracheal groove
Primitive pharynx
Longitudinal depression

32. Tracheoesophageal septum
Left lung bud
Laryngotracheal groove
Laryngotracheal divertuculum
Right lung bud

33. 7th month: surfactant End of 4th week: lung buds 5th week:
Left lung bud→ 2 branches
5th week:
Right lung bud→ 3 branches
Left lung bud→ 8-9 branches
End of 2nd month:
Right lung bud→ 10 branches
End of 6th month: bronchia branch to alveoli
7th month: surfactant

34. Bronchia and their branches
Lengthen
Bronchia and their branches
Pulmonary alveoli
Lung bud
Mesenchyme
Stroma

35. Abnormality of respiratory system
Tracheoesophageal fistula