Kidney development; 3.31 Flashcards
What does the urogenital ridge develop from?
Intermediate mesoderm
What happens during the pronephric phase?
Pronephric duct grows towards the cloaca (genitalia)…pronephric duct later degenerates
What does the pronephric duct become during the mesonephric phase?
Mesonephric or Wolffian duct
What do the mesonephric tubules become in males?
Mesonephric tubules become the efferent ductules of the testes (connect the testis to the ductus deferens)
What does the mesonephric duct become in males?
Ductus (vas) deferens ad ureteric bud (metanephric diverticulum)
What does the mesonephric duct become in females?
Ureteric bud only
What does the ureteric bud (metanephrogenic diverticulum) grow into?
Ureteric bud grows into the intermediate mesoderm (metanephrogenic mesoderm/blastema)
What does the ureteric bud initiate?
Metanephric diverticulum initiates formation of the definitive/permanent kidney (metanephros)
What does the metanephric kidney consist of?
Ureter
Renal pelvis
Major/minor calyces
Collecting duct
What do the nephrons derive from?
Metanephric tubules (from metanephric mesoderm)
What are uriniferous tubules?
Nephrons and collecting ducts
Know that nephrons and collecting ducts develop from different sources
Collecting tubes = metanephric diverticulum
Neprons = metanephric tubules
What is the original supply to the metanephric kidney?
The common iliac…then the body grows caudally and the kidneys “rise”
What causes renal agenesis?
Failure of ureteric bud and metanephric mesoderm to interact
Which kidney more commonly does not form? Which gender is more likely to be born with only one kidney?
The left kidney is more likely to NOT develop
Renal agenesis is more common in males
When should renal agenesis be suspected?
In infants with a single umbilical artery
What causes duplicated or branched ureters and supernumerary kidney?
Bifurcation of ureteric bud prior to interacting with metanephric mesoderm
What causes a pelvic kidney?
Metanephric kidney fails to migrate from pelvis
Metanephric mesoderm fused to form one kidney
What is it called when one kidney crosses over? and fuses to the other kidney? and the arteries are on the medial side?
Crossed ectopic kidney
Fused kidney
Non-rotation
(all three can happen simultaneously)
Where do horseshoe kidneys get stuck during ascension?
IMA
Polycystic Kidney Disease (PCKD)…remember it
It’s not hard
What is seen with multicystic dysplastic kidney disease?
Abnormal dilations of [thin segments] of nephrons
What typically causes a congenital hydroureter? Is it generally bad?
An obstruction of the ureter at the ureteropelvic junction (usually)
Not usually bad…hydronephrosis results
What is the urogenital sinus continuous with?
The allantois…which extends into the body stalk (umbilical cord)