<prompt> Regarding Glomerular filtration rate GFR isNormal glomerular filtration rate is 625 LdayInulin clearance measure the GFRplasma oncotic pressure increases the GFRDiabetes mellitus increases the GFR  <response>: Inulin clearance measure the GFR 31 6- 18-Guy ton 11th, 643-4.5-Ganong 23rd, 302-K Sembulingam 5th. In the average adult human the GFR is about 125mlmin, 1.73 smqcm2 or 180Lday and tubular reabsorption is 178.5 Lday, leaving 1.5Lday of fluid to be excreted in the urineGFR is about 20 of the renal plasma flowGFR Kt Glomerular capillary filtration coefficient x Net filtration pressure Renal blood flow - Average 70 kg man the combined blood flow through both kidney is about 1100 mlmin or about 22 of cardiac out put A substance that is completely filtered but neither reabsorbed nor secreted should be used to measure the GFR i.e. - InulinMeasurement of GFR1. Inulin - clearance test - Most commonly used2. Urea - clearance test3. Cr51 - EDTA clearance test4. Endogenous creatinine clearance test Worth while index of renal functionsIncreased glomerular capillary colloid osmotic pressure decrease GFRTwo factor that influence the glomerular capillary colloid osmotic pressure raises the glomerular capillary colloid osmotic pressure which in turn decreases GFR1. Arterial plasma colloid osmotic pressure oncotic pressure. Increasing the arterial plasma, colloid osmotic pressure raises the glomerular capillary colloid osmotic pressure which in turn decreases GFR2. Fraction of plasma filtered by the glomerular capillaries Fdtration fraction - Increasing the filtration fraction also concentrated the plasma proteins and raise the glomerular colloid osmotic pressure and tend to reduce GFR Sodium, Inulin, Glucose are freely filtered across glomerular capillariesFactors that can Decrease the GFR Renal disease, DM. Hypertension Urinary tract obstruction eg kidney stones Renal blood flow. Increased plasma proteins Arterial pressure has only small effect due to auto regulation Angiotensin II drugs that block angiotensin II formation Sympathetic activity. Vasoconstrictor hormones eg Norepinephrine, epinephrine, endothelin platelet activing factor, PGF2 Increase Bowmans capsule hydrostatic pressureFactor than can Increase the GFR Increased glomerular capillary filtration Coefficient Kt Increased glomerular capillary hydrostatic pressure Endothelial derived Nitric oxide NO- renal vascular resistance -GFR Prostaglandins PGE2 Bradykinin. CAMP, Dopamine, ANP, BNP High protein intake and increased blood glucose - renal blood flow and GFRALSO-REMEMBER Normal filtration fraction varies from 15-20 Normal net filtration pressure is about 20 mmHg varies 15-20 mmHg Kidney receives about 25 of cardiac out put 1.2 - 1.3 litre of blood per minute The tubuloglomerular feed back is mediated by - sensing NaCl concentration in the macula densa The prime driving force for counter current multiplier system is - Reabsorption of Na in thick ascending limb Urinary concentrating ability of the kidney is increased byi ECF volume contraction water deficitii High level of ADHiii High osmolarity of renal medullary interstitial fluid Tc99 DTPA Diethylene- Pentothenic Acid is the agent of choice for assessment of GFR Patient having acute cardiac failure, do not show edema because there is fall in the systemic capillary hydrostatic pressure 