Renal Flashcards
pronephros develops by
Week 4, then degenerates
Mesonephros
interim kidney during 1st trimester, later contributes to male genital system
metanephros
permanent kidney
When does metanephros appear? contiues through
5th week of gestation. Nephrogenesis continues through 32-36 weeks.
When is ureteric bud fully canalized by?
10th week
What is ureteric bud derived from?
caudal end of mesonephric duct
What does ureteric bud give rise to?
ureter + pelvises + calyces + collecting ducts
what does metanephric mesenchyme give rise to?
Glomerulus through to DCT.
what are congenital malformations of kidney often due to?
aberrant interaction between ureteric bud and metanephric mesenchyme.
causes of Potter disease
ARPKD + obstructive uropathy (posterior urethral valves) + bilateral renal agenesis + chronic placental insufficiency
Potter sequence presentation
POTTER (pulmonary hypoplasia, Oligohydramnios (trigger), Twisted face, Twisted Skin, Extremity defects, Renal failure (in utero.
horseshoe kidney assocations
1) hydronephrosis (ureteropelvic junction obstruction.
2) renal stones
3) infection
4) chromosomal aneuploidy syndromes (13,18,21)
5) renal cancer (rarely)
Diagnosis of unilateral renal agenesis
US
cause of unilateral renal agenesis
Ureteric bud fails to develop and induce differentiation of metanephric mesenchyme.
kidney consisting of cysts and connective tissue
multicystic dysplastic kidney
cause of multicystic dysplastic kidney
ureteric bud fails to induce differentiation of metanephric mesenchyme
Causes of duplex collecting system
1) 2 ureteric buds reaching and interacting with metanephric blastema
2) bifurcation of ureteric bud before it enters the metanephric blastema, creating a Y-shpaed bifid ureter.
Why do duplex collecting systems create problems?
1) vesicoureteral reflux
2) ureteral obstruction
3) increased risk for UTIs
what usually happens with congenital solitary functioning kidney?
1) majority asymptomatic
2) compensatory hypertrophy of kidney
3) anomalies in contralateral kidney common though.
which kidney is usually taken during donor transplantation?
left (longer renal vein)
Renal blood flow
renal artery –> segmental artery –> interlobar artery –> arcuate artery –> interlobular artery –> afferent arteriole –> glomerulus –> efferent arteriole –> vasa recta/peritubular capillaries –> venous outflow
angiotensin II affects
1) Potent vasoconstrictor with preferential affects on the efferent arteriole, thus increasing FF to preserve GFR in low vlume states.
2) increases NE release by renal sympathetic nerves, thus stimulating aldosterone release
3) secondary effect is to increase HCO3- reabsorption (permitting contraction alkalosis)
4) Affects baroreceptor function; limits reflex bradycardia.
5) stimulates hypothalamus –> thirst
6) Acts at AT II receptor on vascular smooth muscle –> vasoconstriction –> increased BP.
8) stimulates ADH release from anterior pituitary.
9) increases PCT Na/H activity –> Na, HCO3, H2O reabsorption (can permit contraction alkalosis).
macula densa location
Lines the wall of the cortical thick ascending limb, at the transition to the DCT.
function of macula densa
when GFR drops, NaCl presentation to the macula is reduced , macula densa signals to juxtaglomerular cells in the afferent arteriole, causing them to release renin and activate the RAAS. Thus causing efferent arteriole vasoconstriction and increased GFR.