Reproductive tract Flashcards
The gonads are derived from the urogenital ridge and primordial germ cells, but where does the urogenital ridge arise form?
Intermediate mesoderm in the abdomen
Where do the primordial germ cells come from? Describe the route they take to get from there
the yolk sac- they migrate retroperitoneally
What are primordial germ cells role in development?
They trigger changes in the indifferent gonads to differentiate into girl and boy
What genetic feature causes M and F differentiation
The presence of an SRY gene- found on the Y chromosone, will cause you to develop male characteristics
What changes does the SRY gene cause to create testis development?
The medullary cord will develop into testis Cortical cords wont develop The tunica albergenic will thicken
Both M and F have both mesonephric (wolffian) and paramesonephric (mullerian) ducts, where do they drain into?
They drain into the urogenital sinus at the cloaca
What changes will occur to the meso and paramesonephric ducts if the testis are present and why?
Testis will produce mullerian inhibiting hormone (MIH), which will supresses the development of the paramesonephric/ mullerian duct. It will also produce androgens which will support the mesonephric/ wolffian duct
What will the mesonephric duct become?
The vas deferense
What changes will occur to the the ducts if no testis develop?
Mesonephric (wolffian) regresses due to lack of androgens Paramesonephric will be maintain due to lack of MIH production
What will the paramesonephric/ mullerian duct become?
Uterine/ fallopian tubes and uterus- after fusing and extending cranially to open into abdominal cavity at the ovaries and caudally to open into the cloaca
What happens to the testis after they’ve developed in the abdomen?
Testis pulled down by gubernaculum, the mesonephric duct is taken with it. The paramesnephric duct regresses.
As it descends it pinches off a bit of pertioneum, the processus vaginalis, which travels down with the testis. It normally regresses but can be latent causing a hydrocele.
What are the undifferentiated precursors to the external genitalia?
- Genital tubercle - Genital folds - Genital swelling
Describe the process of external male genitalia development, also what is this process driven by?
- Genital tubercle elongates and will become glans of the penis
- Urogenital folds fuse to become spongey urethra
- Gential swelling (labiosacral folds) fuse to become scrotal swelling and enlarges to accomodate testis
- Process of mainly driven by dihydrotestosterone
Describe the process of female external genital development
Labia majora devlops from genital (labial) swelling and minora develop from genital folds
Genital tubecle becomes the clitoris
The urethrea opens into the vestible
Where do the male accesory glands develop from?
(Prostate, ejaculatory duct, seminal gland)
Prostate and ejaculatory duct come from the urogenital sinus
Seminal gland comes from the mesonephric duct
What is the difference between Kleinefelters syndrome and Turners syndrome?
Kleinfelters= 47 XXY (less strong, generally male but less facial hair, broader hips, breasts, due to less testosterone)
Turners= 45, X (webbed feet, short stature, lack of periods, infertile, broad chest, hormone therapy needed to induce puberty)
