embryology Flashcards
what does the urogenital system develop from
intermediate mesoderm
how do primitive sex cords form
Primordial germ cells migrate to intermediate mesoderm. (Weeks 4-6)
Coelomic epithelium forms genital ridges and somatic supports cells which envelop the PGC’s.
what are PGC
Primordial germs cells = PGC’s
Form egg or sperm
from what do the genital ducts form
Mesonephric duct- males
Paramesonephric duct- female
Ambisexual / Bipotential Phase-
genital ducts and indifferent gonads
when does sexual diffrentiation occur
week 7 onwards
how do primordial follicles in the ovary form
Germ cells differentiate into oogonia and then primary oocytes
Somatic support cells differentiate into granulosa cells and surround the primary oocytes
This forms primordial follicles in the ovary
how do paramesonephric ducts form
Influence of oestrogens stimulates formation of the female external genitalia and development of paramesonephric ducts.
what do the Paramesonephric ducts give rise to
Uterine tubes/oviduct
Uterus
Superior vagina
what are the 3 parts of the paramesonephric ducts
Cranial portion which opens up into the coelomic cavity
Horizontal portion which crosses the mesonephric duct
Caudal portion which fuses with the paramesonephric duct on the opposite side
what does Uterovaginal Canal give rise to
uterus and superior vagina.
abnormal female development examples
double uterus/vagina
bicornate uterus
septated uterus
unicornate uterus
cervical atresia
SRY protein stimulates
formation of sertoli cells for males only
what do sertoli cells do
they make AMH hormone which degenerates paramesonephric duct
and
stimulate gonadal ridge cells to form Leydig cells (testosterone secreting).
testosterone
Induces formation of epididymis, vas deferens, seminal vesicles
