Renal USMLE Flashcards
ureters pass _______ uterine artery and ______ ductus deferens (retroperitoneal)
UNDER,UNDER
mneu: water (ureters) UNDER the bridge (artery, ductus deferens).
total body weight is ____% water
60
total body water is ___ intracellular fluid
2/3
total body water is 1/3 extracellular fluid what portion of this is plasma volume
1/4
ICF=
TBW-ECF
interstitial volume-
ECF-PV
60-40-20 rule (% of body weight)
60% total body water
40% ICF
20% ECF
plasma volume can be measured by this
radiolabeled albumin
extracellular volume can be measured by this
inulin
Cx=
UxV/P=volume of plama from which the substance is cleared completely per unit time
Cx=clearance of X
Ux=urine concentration of X
Px=Plasma concentration of X
V=urine flow rate
if Cx < GFR, then there is net tubular ________ of X
resorption
if Cx > GFR, then there is net tubular ________ of X
secretion
if Cx = GFR, then ___________
no net secretion or reabsorption
glomerular filtration barrier is responsible for filtration of plasma according to these 2 factors
size and net charge
what is the glomerular filtration barrier composed of
1) fenestrated capillary endothelium (size barrier)
2) Fuse basement membrane with heparan sulfate (negative charge barrier)
3) epithelial layer consisting of podocyte foot processes
what barrier of the glomerular filtration barrier is lost in nephrotic syndrome
charge barrier
what are some symptoms of nephrotic syndrome
albuminuria, hypoproteinemia, generalized edema, and hyperlipidemia
what is used to calculate GFR because it is freely filtered and is neither reabsorbed nor secreted
inulin
creatinine clearance is an approximate measure of what
GFR
GFR=
U(inulin)xV/P(inulin)=C(inulin)
effective renal plasma flow (ERPF can be estimated using _____ because it is both filtered and actively secreted in the proximal tubule. All _____ entering the kidney is excreted.
PAH
ERPF=
U(PAH)xV/P(PAH)=C(PAH)
RBF=
RPF/1-Hct
ERPF underestimates true RPF by how much?
~10%