Urogenital development Flashcards
mesonephros
Urinary bladder portion:
urine formation takes place here until week 9
gives rise to:
- excretory tubules that form urine
- mesophrenic ducts that conduct urine to the cloaca where it is excreted into amniotic cavity
metanephros
acts as definitive kidney around week 10
- utretic bud: outgrowth of mesonephric duct
- forms urine CONDUCTING structures: collecting ducts/calyces/renal pelvis/ureter - Metanephric BlastemaL formed from themesenchyme of intermediate mesoderm
- forms urine FORMING structures: nephron tubules
Development (reciprocal induction of eachother)
- RA from Int Mes drives kidney location
- WT1 from Met Blas drives utretic bud dev
- FGF2/BMP7 from utretic bud drives met blas dev
- Wnt6/Wnt9b from utretic bud drives met blas tubule epithelialization
Clinical correlation of kidney development
underinduction
- renal hypoplasia:
- renal agenesis:urine not working, not contributing to amniotic fluid
- oligohydramnios sequence
overinduction:
- bifid ureter: two come off then come together
- ureter duplication:two complete ureters
- fused kidney/ horseshoe: asymptomatic, may constrict SMA
Clinical Correlation of Kidney Ascent
Kidneys formed (metanephros) in the pelvic region
- caudal growth of body makes them appear to ascend
- vascualture formed as body grows and older vasculature deteriorates
- Occasionally they do not deteriorate and you have ACCESSORY RENAL ARTERIES
- Ectopic Kidney or Ureter: abnormal location- still in the pelvis
- can be asymptomatic
- typically to bladder, can go to urethra, vestibule, vagina
Clinical correlations of Urinary Bladder development
Normally in weeks 5-10 the urorectal septum divides the cloaca into
- urogenital sinus: gives rise to urinary bladder and urethra (both the only ENDODERM)
- urogenital sinus goes up into the alantois
- allantois evenually becomes urachus and shouldbecome medial umbilical ligament
- mesonephric duct incorporated into bladder wall forming trigone (endoderm ep overgrows the trigone-this is NOT from UG sinus, from mesonephric duct ) - anorectal canal
CC:
Urachal Fistula, cyst, or sinus
Extrophy of bladder: failure of abdominal wall to close, exposed urinary bladder mucosa
Abdominal Muscle Deficiency Syndrome: Prune Belly, congenital absence of abdominal muscles, intestines and urinary bladder visible
Trigone Development
portion of the mesonephric duct that is incorporated into the bladder wall
overgrown by enderderm epithelium
NOT FROM UG SINUS
genital ridge from what and gives rise to what, and regulation
formed from mesonephros
gives rise two two structures
Gential Ridge CT
-intersititial cells cells (M) and theca calls (F)
Gential RIdge Epithelium
-sustentacular cells (M) and granulosa cells (F)
-both supporting cells
** germ cells NOT from interm meso, from epiblast then micrate to yolk sac
regulated by SRY gene. if SRY gene is blocked, we become male.
Male genital duct
genital ridge froms seminiferous tubules and rete testes
the execretory tube becomes efferect ductys
the mesonephric duct becomes epididymis DD and SV and ED
DRAW
Female genital duct derivation
genital ridge becomes ovaries
paramesonephric duct becomes uterine tubes, uterus and proximal 1.3 of vagina
uterus formed as two paramesonephric ducts fuse
- distal 2.3 vafine formed from urogenital sinus, epithelial endoderm lining
- vagina initially solid, becomes canalized (except hymen)
Clinical correlation with vaginal defects
uterus didelphys with double vagina
indentation- uterus arcuatus
uterus bicornis
uterus bicornis unicollis (1 rudimentary horn)
cervical atresia
vaginal atresia
draw derivation of external genitalia and what things derive from
genital tubercle
- glans penis
- clitoris
genital swelling:
- scrotum
- labium majus
urethral folds
- penile shaft
- labium minus
CC hypospadia and Epispadia
Hypo: males, no dorsal fusion of urethral folds
Epi: no dorsal fusion of urethral folds
-associated with extrophy of bladder
Draw development map
Include Intermediate mesoderm, endoderm, and epiblast
SLIDE 27
