3 Development of the Urinary Tract Flashcards
Embryology
What part of the developing embryo do the 3 separate kidney systems arise from initially?
Intermediate mesoderm
What is the name of the first kidney system to appear and where does it appear in the developing embryo?
Pronephros
in Cervical region
What is the function of the pronephric duct?
Pronephric duct extends from cervical region of cloaca and drives development of NEXT developmental stage
What is the urogenital ridge?
Region of intermediate mesoderm
Gives rise to:
- Embryonic kidney
- Gonad
Where do the mesonephric tubules (stage 2) develop relative to the pronephric region (stage 1)?
Mesonephric tubules caudal to pronephric region
What are the 2 main parts of the embryonic kidney?
Mesonephric tubules and mesonephric duct
What function does the emrbyonic kidney still lack (needs to develop)?
Water conserving function
Why are the mesonephros important (what do they do)? (2)
- Mesonephric duct- important role in development of male reproductive system
- Mesonephric duct sprouts ureteric bud- induces development of definitive kidney
What is the ureteric bud?
Undifferentiated intermediate mesoderm
(caudal to mesonephros)
What is the role of the uteric bud?
Induces development of true kidney
Describe the ‘ascent’ of the kidney (embryologically).
- Metanephric (embryonic) kidney in pelvic region
- Caudal–>cranial shift
- Crosses arterial fork (vessels returning blood from fetus to placenta)
List some major errors which can occur during the the development of the kidney.
- Uteric bud fails to interact with intermediate mesoderm
- Renal agenesis (if bilateral= not compatible with life)
- Migration goes awry
- Duplication defects
- Ectopic ureter
- Cystic disease
Name 2 structural abnormalites that can occur if migration goes wrong.
- Pelvic kidney
- Horseshoe kidney (gets stuck on arteries branching off aorta)
What can occur as a consequence of the ureteric bud splitting? (partial/incomplete)
Ectopic ureteral opening
What is the urogenital sinus and what does it do?
Tract created from hindgut by urorectal septum
- Superior part connects to umbilicus
- Middle (majority of it) differentiates to form bladder
- Inferior part- develops into urethra
What is the urorectal septum and what does it do?
Separates GI tract from urinary genital tract (urogenital sinus)
How does the urogenital sinus develop into the bladder and the urethra in females?
- Mesonephric ducts- reach urogenital sinus
- Ureteric bud sprouts from mesonephric ducts
- Urogenital sinus expands
- Mesonephric duct regresses
- Mesonephric duct regressed, ureteric bud opens into urogenital sinus