urinary embryology Flashcards
Which embryonic layer does the urinary system derive from ?
intermediate mesoderm
what develops from the intermediate mesoderm one after the other from cranial to caudal and n what order ?
pronephros
mesonephros -part of this becomes gonads
metanephros - become kidney and metanephric duct becomes ureter pelvis and collecting ducts
pqrst
Where does the blood supply for embryological urinary system originate from , paired ? segmented ?
-branches of dorsal aorta
in pro/meso - nephros segmentally paired
meta paired
- bs stimulates formation of nephric tubules
what are nephric tubules ?
tubules found inside the nephros and are segmented in pro/meso- nephros
What are urinary ducts ?
these form within mesoderm and drain the nephric tubules as the paired pro/meso- nephric ducts
What are para mesonephric ducts ?
formed in male and female but in male they regress in female they become the uterus
what are paramesonephric ducts also known as ?
mullerian ducts
Embryological development of the testicles
- undifferentiated sex cords align with rete tubules , outer layer tunica albuginea and paramesonephric non functional
- rete tubules and mesonephric tubules interconnected
-epithelial cords ( sex cord ) become seminiferous tubules and mesonephric duct gradually transfors into epididymis and ductus deferens
what is sex determination ?
its a developmental decision that directs the bipotential gonad to develop as a testi or ovary
mammals genetically controlled
some species environmental process
What is sex differentiation ?
induced by products of the gonad
outline the phases of sexual development
-pregonadal phase - germ cells start to migrate from yolk sac
- bipotential gonad - development of the gonadal precursor tissue near kidneys ( genital ridges ) , germ cells migrate to genital ridges
- primary sexual differentiation - differentiation of repro tissue
- secondary sexual differentiation - development of secondary sexual characteristics - phenotypic
What causes a gonad to go down the route of female or male ?
gonads
cells without SRY gene express female genes and inhibit male genes
What are the three levels of sexual dimorphism ?
genetic
gonadal
phenotypic - external features , internal sex organs and sexual differentiation of brain
how is the female brain different from the male in development ?
alpha fetoprotein binds to oestrodiol , this complex can’t cross bbb therefore surge centre can develop this protects the female brain from masculinising effects of oestradiol
how is the male brain different from the female in development ?
testosterone secreted into blood from testes and crosses the bbb converted to oestradiol and dihydrotestosterone this inhibits the development of the surge centre therefore oestradiol masculinises the brain ( defeminisation )
