1. Embryology of the Reproductive Organs
The entire process of sexual development depends on a sequential series of interactions between regulatory factors and genetic machinery.

2. Stages of Sexual Determination (Differentiation)
Chromosomal Determination
XX or XY
Gonadal Determination
Ovary or testes
Phenotypic determination
What do sex organs look like

3. 1. Chromosomal Determination
Ovum
22 Autosomes
1 X chromosome
Sperm
22 Autosomes or
1 Y chromosome
Zygote = 46 XX
46 XY

4. Cleavage

5. Blastocyst

6. Implantation

7. Formation of the Placenta

8. Primordial Germ Cells

9. 3 Week Embryo

10. 6 Weeks embryo

11. 6 weeks

12. Primordial Germ Cells
Genital/GonadalRidge
At Six Weeks

13. TDF

14. Testes Determining Factor
TDF is a gene on the Y chromosome that converts the Gonadal/Genital ridge to a testes
Inside a testes you have:
Seminiferous tubules – Spermatogonia inside
Sertoli cells – Produces MIF (Mullerian inhibiting Factor in embryo.
Interstitial cells – Produce Testosterone

15. Mullerian Duct
Gonadal
Ridge
Wolffian Duct

16. Gonadal Ridge
Mullerian Duct
Wolffian Duct

17. Epidydidimis
Vas deferens
Degenerating Mullerian Duct
Seminal Vesicle

18. Ovaries
Fallopian Tubes
Uterus
Upper Part of Vagina

19. Undifferentiated external
Genital tubercle
Genital groove
Genital fold
Labioscrotal swelling

20. Undifferentiated external
Genital Tubercle
Labioscrotal Swelling
Genital Fold
Genital Groove

21. Undifferentiated Stage
Genital Tubercle
Genital Fold
Genital Groove
Labioscrotal Swelling

22. Genital Tubercle
Genital Fold
Genital Groove
Labioscrotal Swelling
Glans Penis
Penile Rafe
Urethra
Scrotal Sac

23. Genital Tubercle
Genital Fold
Genital Groove
Labioscrotal Swelling
Clitoris
Labia Minor
Vaginal and Urethral Opening
Labia Major

26. 7 Months Months

27. Transabdominal movement
Formation of the Inguinal Canal
Movement into scrotal sac

28. Gubernaculum
Phallus
Inguinal Canal
Testes
Abdominal cavity
Vas deferens

29. Masculanize the Wolffian Duct
Testosterone

30. Masculanize the external genitals

31. Masculanize the Brain