1. Development of Urinary system and reproductive system
1. Development of kidney and ureter
2. Development of urinary bladder and urethra
3. Abnormality in urinary system
4. Development of gonad
5. Development of reproductive tracts
6. Abnormality in reproductive system

2. Head segmentation Nephrotome →
3rd week:
Head segmentation Nephrotome →
Intermediate Pronephros
Mesoderm
Other migration, proliferation Nephrogenic cord
→ Mesonephros and Metanephros

3. Intermediate mesoderm
3rd week
Nephrogenic cord
Urogenital ridge
Intermediate mesoderm
─────→
───→
Intermediate mesoderm
Mesonephric ridge
Gonadial ridge
Urinary system,
Genital excurrent ducts
Gonad
───
Pudendum

4. Mesonephric ridge
Urogenital ridge
Gonadial ridge

5. Mesonephric ridge
Gonadial ridge

6. Development of urinary system
Development of kidney and ureter
1. Pronephros th week
Nephrotome (7-14th Somite)
Pronephric tubule
Pronephric duct
Degeneration in 1 week
Mesonephric
duct

7. Destiny: degeneration
Pronephric
tubule
Pronephros
Time：4th week
Function：no
Destiny: degeneration

8. 2. Mesonephros 14-18th somite
Middle part of nephrogenic cord
80 transverse S-shaped tubule
Mesonephric tubule
Mesonephric duct
Continus to pronephric duct
Inner end form renal capsule
Glomerulus
Outer end bind to mesonephric duct
The end bind to cloaca

9. Time： Function: Destiny: transient urinary Most degeneration,
end of 4th week
Function:
transient urinary
Destiny:
Most degeneration,
Small part form male excurrent duct
Mesonephric duct
Mesonephric tubule

10. 3.Metanephros Time：begin at 5th week, Function：begin at 3th month,
exist forever
Function：begin at 3th month,
urinary function
Position：rise gradually
Metanephros

11. End of mesonephric duct
（adjacent to cloaca）
Origin
one
Ureteric bud
Prolong
Ureter
Embranchment ＞12
Renal pelvis, renal calyce
（The end branched as T）
Collecting tube

12. + Origin two Metanephrogenic blastema Cap-shaped cell cluster
(Mesoderm of the mesonephric ridge)
Metanephrogenic blastema
Cap-shaped cell cluster
S-shaped tubule
Bind to collecting tubule
Renal capsule
Glomerulus +
Renal tubule
Renal corpuscle
Nephron

13. Metanephrogenic blastema
Mesonephric tubule
Collecting tubule
Renal pelvis
Renal calyce
Ureteric bud

14. Formation and rising of metanephros

15. Development of urinary bladder and urethra
Male
Female
Upper：
Middle:
Lower:
Urinary bladder
Upper part
of urethra
Lower part
Urethra
Vestibule of vagina
Urogenital sinus
Anorectal canal
4-7th week
Urorectal septum
Cloaca

16. Evolvement of male urogenital sinusB C D E

17. Positional evolvement of Ureter and Mesonephric duct

18. Abnormality
　Double ureter
　Urachal fistula
　Exstrophy of bladder
　Polycystic kidney
　Horseshoe kidney
　Single kidney

19. Polycystic kidney

20. Horseshoe kidney

21. Single kidney
Right single kidney
Left single kidney

22. Ectopic kidney

23. Double ureter
Ureter

24. Urachal fistula

25. Exstrophy of bladder

26. Development of gonad Gonad differentiation at 7th week
Developmental stage：
Sex undifferentiated stage→ Sex differentiated stage
Reproductive tracts：２ → １
Proper current： → Feamle

27. Endoderm cells of yolk sac
Development of gonad
Endoderm cells of yolk sac
4th week
Proliferation, differentiation
Primordial germ cells
6th week
Migration in one week
１.Development of
undifferentiated gonad
Gonadial ridge
6th week
Primary sex cord
Superficial epithelium →cell cords

28. Large and round endoderm cells in yolk sac
Primordial germ cells
Large and round endoderm cells in yolk sac

29. Migration of primordial germ cells
6th week

30. Histocompatibility Y antigen
H-Y antigen determine the differentiation to testis
The gene of H-Y antigen located at Y chromosome
The cell membrane of the cell which sex chromosome
is XY possesses H-Y antigen
Primary sex cord H-Y antigen proliferation
seminiferous tubule

31. ２. Development of testis Primary sex cord (H-Y antigen) 7th week
Separated from surface
Mesenchymal cell
Interstitial cell
Cells of sex cord
Primordial germ cells
Sustantacular cell
Spermatogonium + +
Testis

32. ３. Development of ovary Superficial epithelium + + Primary sex cord
Secondary sex cord (cortical cord)
Primary sex cord
(No H-Y antigen)
After 10th week
Primordial follicle
16th week
Mesenchymal cells
Stroma
Degeneration
Cells of sex cord
Primordial germ cells
Ovary + +
Follicular cells
Oogonium

33. Cortex
Medulla
Cortical
Cord
Ovary
Testis
Rete testis
Tubule rectus
Follicle
Seminiferous
tubule

34. Ovary Testis Rete testis Primary oocyte Follicular cell Follicle
Tubule rectus
Follicle
Seminiferous
tubule
Spermatogonium
Primary oocyte
Sustantacular cell
Follicular cell
Follicle
Seminiferous tubule

35. ４. Descend of testis and ovary Embryo →lengthen Gubernaculum →shorten
7th to 8th month → Scrotum

36. Paramesonephric tubule
Development of reproductive tracts
1. Undifferentiated stage:
Mesonephric tubule
Gonad
Mesonephric duct
Paramesonephric tubule
Sinus tubercle
Urogenital sinus
B. Female
A. Male

37. Paramesonephric duct： Mesonephric ducts and tubules
２. Differentiation of female reproductive tract
End of upper segment：Fimbria
Upper and middle segment：oviduct
Lower segment： Uterus
End： Vaginal fornix
Paramesonephric duct：
Sinus tubercle：
Vaginal plate Vagina
Mesonephric ducts and tubules
Degeneration

38. 3. Differentiation of male reproductive tract
Head ── Epididymal duct
Tail ── Spermaduct
Metanephric duct
Most of →degeneration
Some of → Efferent ducts
Mespnephric tubules
Paramesonephric duct
Degeneration

39. Ovary
Testis
Urogenital sinus
Urogenital sinus
Oviduct
Spermaduct
Uterus
Vaginal plate
Efferent duct
Epididymal duct

40. Abnormality of reproductive system
1. Cryptorchidism
2. Congenital inguinal hernia
3. Double uterus
4. Vaginal atresia
5. Hypospadias
6. Hermaphroditism

41. Cryptorchidism

42. Congenital inguinal hernia

43. Double uterus

44. Vaginal atresia

45. Hypospadias

46. Hermaphroditism