52) .IN THE NORMAL KIDNEY

[Editor]

a) blood flow can be estimated from inulin clearance
b) the plasma concentration of para aminohippuric acid is similiar to that of creatinine
c) urea clearance is decreased by increased ADH secretion
d) glucose clearance is equel to the glomerular filtration rate
e) inulin clearance is increased by decreased ADH secretion

[Editor]

ftff
PAH clearance provides measurement of the renal plasma flow.Renal blood flow can be derived by RPFX1/1-Hct.Urea is filtered in the glomerulus and 50% of the load is reabsorbed in the proximal tubules, the rest of the tubule being impermeable to urea and thereby increasing the urea conc in the tubules. In the medullary portion of the collecting duct urea moves to the interstitium, movement being facilitated by ADH.In the absence of ADH, urea moves into the tubule whereas increased ADH facilitates hypertonic medullary interstitium contributed by urea and thereby urea clearance is decreased.Inulin,a poly saccharide of 5500 daltons, is filtered at the glomerulus,not secreted, not absorbed and not metabolised by the kidney. Its clearance measures the GFR.Since ADH does influence the GFR,inulin clearance is not dependent on ADH.

[Tonic]

Anyone know where PAH is produced in the body and if it is really in the same concentration as creatinine?