Nephrology Flashcards
At what week does the PRONEPHROS degenerate?
4 weeks
What structure is the “permanent” kidney?
Metanephros
appears at week 5
What structures are derived from the ureteric bud?
Ureters
Pelvises
Calyces
Collecting ducts
The metanephric mesenchyme/ blastema gives rise to
glomerulus –> DCT
Obstruction of this structure is the most common cause of prenatal hydronephrosis
Ureteropelvic junction
Compression of the developing fetus caused by oligohydramnios –> limb deformities
Potter sequence (syndrome)
What conditions are associated with Potter sequence?
POTTER:
Pulmonary hypoplasia Oligohydramnios Twisted face Twisted skin Extremity defects Renal failure
A condition in which the inferior poles of the kidneys fuse and are trapped under the INFERIOR MESENTERIC ARTERY. Associated with hydronephrosis.
Horshoe kidney
This is the most common cause of bladder outlet obstruction. Presents with bilateral hydronephrosis and oligohydramnios
posterior urethral membrane
Why is the left kidney used for living donor transplant?
because it has a longer renal vein.
The left renal vein receives 2 additional veins: left suprarenal an left gonadal
3 most common points of ureteral obstruction
ureteropelvic junction
pelvic inlet
ureterovesical junction
What is the effect of prostaglandin in the kidneys
preferentially dilates AFFERENT arteriole
(increase RPF and GFR, no change in FF)
Prostaglandin is inhibited by by NSAIDS –> constriction
What is the effect of ANGIOTENSIN II in the kidneys
Preferentially constricts EFFERENT arteriole
(decreased RPF, increased GFR and FF)
inhibited by ACE inhibs
Site where all glucose and amino acids, most HCO3, Na, Cl, PO4, K, H2O, and uric acid are reabsorbed. generation and secretion of NH3
PCT
Effect of PTH in PCT
increase PO4 EXCRETION
Effect of angiotensin II in PCT
increase Na, H2O, and HCO3 reabsorption
This is a reabsorption defect in PCT causing proximal RTA –> hypophosphatemia, osteopenia (excretes everything PCT reabsorbs)
Fanconi syndrome
This is where passive reabsorption of H2O happens. Concentrating segment –> hypertonic urine.
Thin descending loop of Henle
Site of Na, K, Cl reabsorption and paracellular reabsorption of Mg and Ca
Thick ascending loop of Henle
What condition affects the Na/K/2Cl cotransport in the thick ascending loop of Henle causing metabolic acidosis, hypoK, hyperCa
Barter syndrome
Diluting segment of the nephron. Reabsorption of Na, Cl, Ca
DCT
What is the effect of PTH in the DCT?
increase Na/Ca exchange –> increased Ca reabsorption
This part of the nephron is regulated by aldosterone causing reabsorption of Na in exchange for K and H2O
Collecting tubules
This is a reabsorption defect of NaCl in DCT causing metabolic alkalosis, hypoMg, hypoK, hypoCa
Gitelman syndrome
Gain of function mutation causing increase Na reabsorption in collecting tubules
Liddle syndrome
Met alk, hypoK, HPN
Hereditary 11B-HSD deficiency –> increase in cortisol –> increase mineralocorticoid receptor activity
Syndrome of apparent mineralocorticoid excess
What activates RAAS?
decrease BP and NaCl delivery (macula densa)
increase sympathetic tone (B1-receptors)
