Embryology

Question 1

The presence of testosterone causes the obliteration of which duct?

What happens in the absence of testosterone?

Answer 1

Paramesonephric ducts - therefore the female internal genitalia does not form

absence causes obliteration of the mesonephric ducts

Question 2

The failure of the paramesonephric ducts to merge in the midline or to canalise causes vaginal and uterine abnormalities, give some examples of these

Answer 2

1. Uterus didelphys with double vagina (both doubled)
2. Uterus arcuatus (indentation from above)
3. Uterus bicornis (1 vagina but 2 uteruses)
4. Uterus bicornis unicollis (1 rudimentary horn, so only 1 is functional)
5. Atresia of cervix (not open - failure to canalise)
6. Atresia of vagina (failure to canalise at level of the vagina instead)

Question 3

From which duct do the uterus, vagina, and the uterine tubes develop?

Answer 3

Paramesonephric duct

when it merges in the midline