Kidney Embryology Flashcards
What is the first developmental renal structure?
Pronephros, which degenerates after week 4
What functions as the interim kidney for the first trimester?
Mesonephros.
What does the mesonephros later contribute to?
Male genital system
What is the permanent renal structure? When does it develop?
Metanephros. First appears in 5th week of gestation, nephrogenesis continues through 32-36 weeks.
Where does the ureteric bud come from?
Caudal end of of mesonephric duct
What does the ureteric bud give rise and by when?
Gives rise to ureter, pelvises, calyces, collecting ducts. Is fully canalized by 10th week
Where does glomerus to DCT arise from?
Metanephric mesenchyme; ureteric bud interacts with this tissue, interaction induces differentiation and formation of glomerulus to DCT.
Abnormalities in interaction –> severe congen. malformations
Where is the last place to canalize?
Ureteropelvic junction
What does inability to produce urine in utero lead to?
Oligohydramnios –> compression of developing fetus –> limb deformities, facial anomalies (low set ears and retrognathia), compression of chest, lack of amniotic fluid providing stretch to the lungs –> pulmonary hypoplasia.
What are some causes of potter sequence?
obstructive uropathy (eg posterior urethral valves)
ARPKD
bilateral renal agenesis
What is horseshoe kidney?
Fusion of inferior poles of kidney
Where is horseshoe kidney located?
Under IMA - gets trapped and can’t rise farther. Remains low in abdomen.
What chromosomal abnormalities are associated with horseshoe kidney?
Anueploidy syndromes - Down, Edwards, Patau, Turner
What renal conditions are associated with horsehose kidney?
Ureteropelvic junction obstruction, hydronephrosis, renal stones, infection, rarely renal cancer
What causes multicystic dysplastic kidney?
Abnormal interaction between ureteric bud and metanephric mesenchyme.
What is the the presentation of multi-cystic dysplastic kidney?
Non functional kidney composed of cysts and connective tissue. Unilateral = most common. Asx w/ compensatory hypertrophy of contralateral kidney.
What are two causes of duplex collecting system?
- Bifurcation of ureteric bud before it enters metanephric blastema - Y shaped bifid ureter.
- Two uretric buds reach metanephric blastema and interact.
What are sx of duplex collecting system?
Vesicoureteral reflux, and/or ureteral obstruction, incr risk for UTIs.
