Question

• Describe the embryonic development of the male and female reproductive systems

Answer 1

• The male and female reproductive system develop initially embryonically indifferent . It is the product of Y chromosome SRY gene that make the difference.
• Paired mesonephric ducts ( Wolffian ducts ) and paramesonephric duct( Mullerian ducts) contribute to the majority of male and female internal genital tract respectively .
• Testes is the male gonad and ovaries are female gonad.Male embryo consist of XY chromosome , which consist of Y chromosome contains the SRY gene , which stimulate the development of primitive sex cord to form testis cord.
• Portion of testis cord break off to form future retetestis .The remaining cord contais two type of cells , they are sertoli cell and germ cells.
• As females doesnot contain Y chromosome , there will be absence of SRY gene and no testis cord development, instead epithelium of gonad continue to proliferate and form cortical cord.
• Presence of testosterone in the male , which is produced by Leydig cells , the mesonephric duct develop to form male genital ducts .This gives rise to efferent ductules , epidiymis , vas deferens and seminal vesicle.
• In females , absence of anti -mullerian hormone also allow for development of paramesonephric duct, these duct have three parts,
• Cranial part becomes the fallopian tube, horizontal part becomes fallopian tube , caudal fuses to form uterus , cervix and 1/3 of birth canal .
• In male external genitalia dvelopment includes , rapid elongation of genital tubercle , which becomes the phallus , genital swelling become scrotal swelling.
• Dihydrotestosterone and estrogen are responsible for development of external genitalia in male and female respectively.
• In female , labia majora and labia minora forms , urethral groove become open forming vestibule into which urethra open.
• Finally there will be descend of gonad , in males it is through inguinal canal and in females ovaries migrate caudally.