First Aid - Embryology Flashcards
When does the Pronephros develop and what does it become?
Week 4; then degrades
What is the function and fate of the mesonephros?
Functions as interim kidney for first trimester, later contributes to male genitalia
When does the metanephros develop and what does it become?
Week 5; permanent; becomes kidney; nephrogenesis continues through 32-36 weeks of gestation.
What are two important embryologic structures associated with the kidneys?
Ureteric bud and metanephric mesenchyme. Aberrant interaction between these two tissues may result in several congenital malformations of the kidneys.
Where does the Ureteric bud derive from and what structures does it give rise to?
The ureteric bud is derived from the caudal end of the mesonephric duct. It gives rise to the ureter, pelvises, calyces, and collecting ducts. Fully canalized by 10th week.
What does the metanephric mesenchyme give rise to?
The ureteric bud interacts with the metanephric mesenchyme which then differentiates and forms the structures from the glomerulus to the distal convoluted tubule.
What is the etiology of Potter Syndrome?
Oligohydramnios -> compression of developing fetus (due to lack of amniotic fluid production) -> limb deformities, facial anomalies (low set ears, retrognathia), and compression of chest -> pulmonary hypoplasia (cause of death)
What causes Potter syndrome?
ARPKD (Autosomal Recessive Polycystic Kidney Disease), posterior urethral valves, bilateral renal agenesis
What’s the mnemonic for Potter syndrome?
Babies who can’t “Pee” inter develop Potter syndrome. Pulmonary hypoplasia, Oligohydramnios, Twisted face, Twisted skin, Extremity defects, Renal failure (POTTER).
What is horseshoe kidney?
Inferior poles of both kidneys fuse. Fused kidneys get trapped under inferior mesenteric artery during ascension and remain low in abdomen. Normal function but increased risk of ureteropelvic junction obstruction, hydronephrosis, renal stones, renal cancer (Wilms tumor). Associated with Turner syndrome.
What is multi cystic dysplastic kidney and what causes it?
A nonfunctioning kidney consisting of cysts and connective tissue. Generally asymptomatic with compensatory hypertrophy of contralateral kidney. Results from abnormal interaction of ureteric bud and metanephric mesenchyme.
What is significant about the development of the ureteropelvic junction?
The ureteropelvic junction is the last to canalize and thus is the most common site of obstruction (hydronephrosis) in the fetus.
