2/28 renal Flashcards
Order of metanephros, pronephros, mesonephros.
1-pronephros
2-mesonephros
3-metanephros
What does mesonephros eventually contribute to?
Wolffian duct
-internal male structure except prostate.
When does the metanephros show up?
5th week.
What does ureteric bud give rise to?
From collecting duct til ureter (including ureter).
What does Metanephric mesenchyme give rise to?
All of nephron until/except collecting duct.
-starting from glomerulus going til (& including) DCT.
Last to canalize in fetal kidney?
Ureteropelvic junction = most common site of obstruction (hydronephrosis) in fetus.
- Cause of death in oligohydramnios?
- Causes?
- pulmonary hypoplasia
- ARPKD, posterior urethral valves, bilateral renal agenesis.
Horseshoe kidney
- what stops its ascent?
- associated w/what syndrome?
- is renal function affected?
- which poles commonly fused?
- inf mesenteric art.
- Turners
- no
- inf. poles
Multicystic dysplastic kidney
- cause?
- function of kidney affected?
- if bilateral, dont confuse w/what?
- Due to abnormal interaction between ureteric bud and metanephric mesenchyme.
- leads to non-functional kidney.
- polycystic kidney .disease
Which kidney is taken during a transplant and why?
Left kidney, longer renal vein.
Renal arterial supply:
Ab. aorta => renal => segmental => lobar => interlobar => arcuate => interlobar => afferent => glomerulus.
Renal venous path:
glomerulus => efferent arteriole => interlobar v => arcuate => interlobar => renal => IVC
Ureters course:
- pass UNDER uterine artery and under ductus deferens (retroperitoneal).
- pass OVER the common/external iliac vessels.
- “Water (ureters) under the bridge (uterine artery, vas deferens).”
Gynecologic procedures involving ligation of the uterine vessels: watch out not to damage what?
-ureter, which passes just under uterine artery.
What type of epithelium do ureters have?
-transitional
- How much of total body weight is water?
- What fraction is intra & extracellular?
- 60%
- 2/3 intracellular (40% body weight)
- 1/3 extracellular (20% body weight)
Extracellular fluid
-what fraction is plasma volume vs interstitial volume?
- 1/4th plasma volume (5% body weight)
- 3/4th interstitial volume (15% body weight)
mnemonic for % of body weight for total body water/ICF/ECF.
60–40–20 rule (% of body weight):
- 60% total body water
- 40% ICF
- 20% ECF
- Whats used to measure plasma vollume?
- Whats used to measure extracell. volume?
- radiolabeled albumin
- inulin
Normal plasma osmolarity
Osmolarity = 290 mOsm/L.
-about double your serum Na b/c Na has +2 charge.
What gives basement membrane of glomerulus a negative charge?
heparan sulfate
Renal clearance equation:
Cx = UxV/Px
- Cx = clearance of X (mL/min).
- Ux = urine concentration of X (mg/mL).
- V = urine flow rate (mL/min).
- Px = plasma concentration of X (mg/mL).
*-so basically: urine conc = what you take out / what you put in. Then you multiply by how fast you’re doing it. And thats clearance.
- Cx < GFR:
- Cx > GFR:
- Cx = GFR:
- net tubular reabsorption of X.
- net tubular secretion of X.
- no net secretion or reabsorption (like inulin)
- oncotic pressure of bowmans space?
- whats normal GFR?
- normally = 0
- 100ml/min
Is serum creatinine a sensitive indicator for renal function?
- relationship btwn GFR & creatinine is NOT linear.
- you can have normal creatinine level even w/50% loss of renal fcn.
- So after you lose a significant amount of GFR, after that, small decreases in GFR can cause big increases in blood creatinine levels.
- *serum creatinine is not a sensitive indicator for decreasing GFR when creatinine levels are normal.
Effective renal plasma flow
-estimated using what?
- clearance of para-aminohippuric acid (PAH).
- ERPF underestimates true renal plasma flow (RPF) by ~10%.
- renal blood flow equation
- is ERPF an accurate measure of renal plasma flow (RPF)?
RBF = RPF/(1 - Hct) or RBF(1-hct) = RPF
-ERPF underestimates true renal plasma flow (RPF) by ~10%.
Filtration fraction equation:
FF = GFR/RPF
-Filtered load equation
-Excretion rate = V × Ux
.
- Filtered load = GFR × Px
- Excretion rate = V × Ux
- Ux = urine concentration of X (mg/mL).
- V = urine flow rate (mL/min).
- Px = plasma concentration of X (mg/mL).
- How is glucose resorbed in kidney?
- At what plasma glucose does glucosuria begin?
- At what plasma glucose are all transported fully saturated?
-Glucose at a normal plasma level is completely reabsorbed in proximal tubule by Na+/glucose
cotransport.
-200 mg/dL
-375 mg/dL
Glucose and amino acid resorption in pregnancy:
Dec. reabsorption of glucose and amino acids in the proximal tubule glucosuria and aminoaciduria.
-this is normal in pregnancy.
Amino acid resorption in nephron:
-Sodium-dependent transporters in proximal tubule reabsorb amino acids.
Hartnup disease:
- Autosomal recessive.
- Deficiency of neutral amino acid (ie. tryptophan) transporters in PCT and on enterocytes.
- Leads to neutral aminoaciduria & dec. absorption from the gut
- Results in pellagra-like symptoms; treat with high-protein diet and nicotinic acid.
What does the PCT secrete?
NH3
-buffer for secreted H+
PTH effect on PCT?
- inhibits Na+/PO43– cotransport → PO43– excretion.
* remember, PTH inc. phosphate excretion but inc. Ca resorption. Trying to inc. free Ca.
AT 2 effect on PCT?
stimulates Na+/H+ exchange → ↑ Na+, H2O, and HCO3
- reabsorption (permitting contraction alkalosis).
- so it inc. Na, water, and bicarb resorption in exchange for secreting H.
- permits contraction alkalosis.
How much of filtered Na is resorbed in PCT?
-65-80%
- What generates the (+) luminal potential in the Thick ascending loop of Henle?
- What does this (+) luminal potential accomplish?
- K+ backleak.
- paracellular Mg & Ca resorption.
*thats why loop diuretics cause you to lose cations.