Urinary System Flashcards
Pronephros-till when does it exist
Until 4 weeks, then degenerates
Mesonephros function and existence
Functions as interim kidney for 1st trimester and then regresses.
In males: the mesonephric (Wolffian) ducts persist which later contributes to male genital sysytem.
Mesonephros role in urinary system
Gives rise to ureteric bud which gives rise to collecting part of kidney(pelvis of kidney, major and minor calyces, collecting tubules)- fully canalised by 10th week.
Gives rise to ureteric diverticula which form the ureters.
Metanephros forms
- Definitive adult kidney,
2. Renal parenchyma(nephros- PCT, DCT, Henles loop, glomerulus)
Urogenital sinus develops into
- Bladder
2. Urethra and allantois
Each kidney ascends the post abd wall to reach its normal position in the loin
Between 5 to 8 weeks of embryonic development
Kidney rotates, 90 degrees so that its hilum faces medially instead of ventrally as it did previously.
5 to 8 weeks of embryonic development
Nonunion of secretory and collecting part of kidney results in
Congenital polycystic kidney
Urinary bladder is formed from
The upper portion of the urogenital sinus which is continuous with allantois.
Epithelium of the urinary bladder develops from
The cranial part of the vesicourethral canal(endoderm).
Epithelium of trigone of bladder is derived from
The absorbed mesonephric ducts (mesoderm).
Muscular and serous coats are derived from
Splanchnopleuric intraembryonic mesoderm
Posterior wall of prostatic urethra is derived from
Absorbed mesonephric ducts (mesoderm).
Female urethra derived from
Caudal part of vesicourethral canal.
Pelvic part of definitive urogenital sinus.
Prostatic urethra derived from:
- Above openings of ejaculatory ducts(colliculus seminalis)
- Below openings of ejaculatory ducts
- Caudal part of vesicourethral canal.
2. Upper pelvic part of definitive urogenital sinus.
