Topic 7.7 Flashcards
(60 cards)
Which factors causes the testes to begin devlping?
TDF = testis determining factor
When does TDF appear?
7th gestational week
When do the ovaries start developing?
At 9th week of gestational dvlpmt
How does TDF influence differenciation?
by associating with SF1 and upregulating genes like SOX9
What is the role of SOX9? (2)
- Induces development of primary sex cords
- Inhibits beta-catenin which mediates female development
What are the 2 hormones required for the development of male phenotype?
- Antimullerian hormone (AMH)
- Testosterone
Which cells secrete AMH?
sertoli cells
Which cells secrete testosterone?
leydig cells
What is the role of testosterone?
It promotes growth and differentiation of wolffian duct
What does the wolffian duct give rise to? (4)
- Epididymis
- vas deferens
- seminal vesicles
- ejaculatory ducts
What converts testosterone to DHT? (3)
- prostate
- seminal vesicles
- epididymis
What happens if there is no SRY?
R-spondin 1 and Wnt4 act together to stabilize B-catenin
What does B-catenin do?
It inhibits SOX-9 and induces the development of female phenotype
What do the indifferent gonads consist of?
outer cortex and inner medulla
Where are the indifferent gonads located?
near the hindgut in the gonadal ridge
Which part of the indifferent gonads to testis develop from?
from the medulla
Which part of the indifferent gonads to ovary develop from?
form the cortex
How do semineferous tubes form?
From excavation of the primitive sex chords
How do spermatogonia form?
From primordial germ cells
How do sertoli cells form?
from sex cords
How do rete testis form?
from dorsal part of the gonas
how do efferent ductules form?
from mesonephric tubules
when do male fetal testes begin to secrete testosterone?
at the 7th gestational week
Which stucture first starts secreting testosterone in fetal life?
the genital ridges
