Embryology Flashcards
Which layer of the 3 layer embryo does the reproductive system originate?
- intermediate mesoderm
The urogenital ridge forms what?
- gonads
- ductal system
What is the common embryological cavity in the urogenital system
- cloaca
The urinary system is more __medial/lateral__ than the genital
- lateral
When does sex differentiation appear?
- after week 7
Ductal system in males?
- mesonephric
- aka. wollifian
Ductal system in females?
- paramesonephric
In terms of sex differentiation in the gonadal system, female changes occur where compared to males?
- female - cortex
- male - medulla
What gene leads to sex differentiation?
- SRY gene
(sex, region, y) transcription factor, presence leads to testes determining factor
Male development is triggered by what?
- SRY gene
Sertoli cells release?
- AMH hormone
- segregates the paramesonephric ducts
Leydig cells secrete what?
- testosterone
- maintenance and growth of the mesonephric ducts (epididymis, vas deferents etc)
What hormone is responsible for the development of the external male genitialial?
-testostorone - dihydrotestosterone
Describe the formation of the external male genitalia?
- proximal to distal zipping of the urethral groove
- forms the stony urethra
Define hydrospadius?
- abnormal external urethral opening on ventral aspect of penis
Follicular cell development in females in caused by what?
- absence of SRY gene
- follicular development
- leads to oestrogen secretion
Oestrogen is responsible for what in female development?
- external genital
- maintenance of paramesonephric ducts
Which stage is the primordial follicles halted in?
- prophase 1
3 regions of the paramesonephric ducts?
- cranial (opening into the peritoneal cavity)
- horizontal (crosses mesonephric duct)
- caudal (fuses with duct on opposite site, forming uterovaginal canal)
What guides descent of the gonads in males and females?
- gubernaculum
Cryptorchidism?
- failure in descent of the testes
- gubernaculum normally aids descent
