Development of urethra with male and female developmental difference . The development of male & female urethra is different . The female urethra is short & its development is very simple .but male urethra is long & its development is complicated The epithelium of entire female urethra & most of the male urethra is derived from urogenital sinus Urogenital sinus is developed from cloaca Cloaca : part of hindgut caudal to attachment of allantois, which is common chamber for hindgut & urinary system

1. Development of urethra

2. Topics included in this video
• Topics included in this video
• Steps of urethral development
• summary
• Development of male and female urethra
• Difference between male and female development of urethra
• Development Histological approach

3. The development of male & female urethra is different .

4. The female urethra is short
&
its development is very simple

5. but male urethra is long
&
its development is complicated

6. The development of male urethra is intimately related
to the development of external genital organs

7. The epithelium of entire female urethra
&
most of the male urethra is derived from urogenital sinus

8. Urogenital sinus is developed from cloaca

10. Cloaca :
part of hindgut caudal to
attachment of allantois,
which is common chamber
for hindgut & urinary
system

11. Cloaca is divided into 2 parts by urorectal septum
ventral part: primitive urogenital sinus Dorsal part: primitive rectum

12. Parts of primitive urogenital sinus :
vesico-urethral canal & definitive urogenital sinus

13. For explaining development Primitive urogenital sinus can be divided into 4 part
From above down ward

14. Cloaca
Primitive urogenital sinus Primitive rectum
Rectum & upper part of anal canal
Upper part of primitive urogenital sinus is known as Vesico-urethral canal : it has 2 part
Upper part of vesico-urethral canal
Lower part of vesico-urethral canal
Lower part of primitive urogenital sinus is known as Definitive urogenital sinus: it has 2 part
Pelvic part of definitive urogenital sinus
Phallic part of definitive urogenital sinus

15. Structures derive from primitive urogenital sinus
• From above down ward
• Upper part of vesico-urethral canal : Urinary bladder
• Lower part of vesico-urethral canal
• Pelvic part of definitive urogenital sinus Urethra
• Phallic part of definitive urogenital sinus

16. SN: only the lining epithelium of the urethra is derived
from endoderm of urogenital sinus
Connective tissue and smooth muscles of urethra are
derived from surrounding splanchnopleuric layer of
lateral plate mesoderm (intraembryonic mesoderm )

17. only the lining epithelium of the urethra is derived from endoderm of urogenital
sinus
Connective tissue and smooth muscles of urethra are derived from surrounding
splanchnopleuric layer of lateral plate mesoderm (intraembryonic mesoderm )

19. Development of female urethra
Parts of primitive urogenital
sinus
Female urethra
Lower part of vesico-urethral
canal
Most of the proximal part of female urethra
Pelvic part of definitive
urogenital sinus
Small distal part of female urethra
Phallic part of definitive
urogenital sinus
Vestibule of female external genitalia into which
the urethra is opened (external opening )

22. Development of male urethra
Parts of primitive urogenital sinus Male urethra
Lower part of vesico-urethral canal Prostatic part of urethra up to the level of
opening of ejaculatory duct
Pelvic part of definitive urogenital sinus Prostatic part of urethra below the opening of
ejaculatory duct and membranous part of
urethra
Phallic part of definitive urogenital sinus Penile part of urethra
Surface ectoderm Terminal part (which occupies the glans penis )

25. Parts of primitive
urogenital sinus
Male urethra Female urethra
Lower part of vesico-
urethral canal
Prostatic part of
urethra up to the level
of opening of
ejaculatory duct
Most of the part of female
urethra (upper part)

26. Parts of primitive
urogenital sinus
Male urethra Female urethra
Pelvic part of definitive
urogenital sinus
Prostatic part of
urethra below the
opening of ejaculatory
duct and membranous
part of urethra
Small part of female urethra
(lower part)

27. Parts of primitive
urogenital sinus
Male urethra Female urethra
Phallic part of definitive
urogenital sinus
Penile part of urethra Vestibule of female external
genitalia into which the
urethra is opened (external
opening )

28. Parts of primitive
urogenital sinus
Male urethra Female urethra
Surface ectoderm Terminal part (which
occupies the glans
penis )
×

29. Histology of Male
urethra
Histology of Female urethra
Most of the lining
epithelium is derived
from endoderm of
urogenital sinus except
terminal part which is
derived from surface
ectoderm
Entire lining epithelium is
derived from endoderm of
urogenital sinus

30. Rest of the histological layer of male and female
urethra is derived from
splanchnopleuric layer of lateral plate mesoderm

31. Cloaca

32. Urorectal septum