Pbs Pgc Gfr

Equations Sheet Block 2 Mass Balance: Amount IN= Amount OUT Excretion Rate = Us * V Substance (mM)

Us= Urine Conc. of V= Volume Rate (ml/min)

Fractional Excretion= Excretion/ Filtered load of Substance (mM) = (Us * V)/ (Ps * GFR) Rate (ml/min)

Ps= Plasma Conc. GFR= Glomerular Filtr.

Excretion= Filtration – Reabsorption + Secretion Filtration: GlomerulusBowmans caps Reabsorption: Tubule Pericapillary Sucretion: Pericapillary Tubule Excretion: Remove from body via tubule Net Reabsorption Rate= Filtered Load – Excretion rate (GFR*Ps)-(Us*V) Net Secretion Rate= Excretion Rate- Filtered Load (Us *V)- (GFR* Ps) Renal Clearance: Cs=( Us * V)/Ps Ps=mg/ml C=ml/min Volume of plasma that is completely cleared of substance by kidneys per unit time Osmolar Clearance: clearance (ml/min)

Us= mg/ml V= ml/min

Cosm = (Uosm * V)/Posm Cosm= osmolar Posm= Plasma osmolarity

(mOsm/l) Uosm= Urine Osmolarity (mOsm/l) V= Urine Volume Rate (ml/min) Free Water Clearance: Clearance (ml/min) Rate which solute free h2o excreted (ml/min)

CH2O= V- Cosm

Free H2o V= Urine Volume Rate

Cosm= osmolar clearance (ml/min) Filtration Fraction: GFR/ RPF rate

GFR: Glomerular Filtration RPF: Renal plasma flow

Glomerular Filtration Rate: pressure glomerulus

GFR=Kf [Pgc – πgc – Pbs] Pgc - hydrostatic πgc – oncotic pressure glomerulus Pbs- hydrostatic pressure bowmans

Glomerular Filtration Rate:GFR= (Us *V)/Ps =Cs If Cs=Ps clearance= Amount in plasma Renal Plasma Flow: cleared from plasma Renal Plasma Flow:

RPF= (UPAH * V)/PPAH = Cs for PAH because 90% RPF= (Us * V)/Ps =

Renal Blood Flow= (Renal Artery Pressure- Renal Vein Pressure)/Total Renal Vascular Resistance Cardiac Output: CO= HR x SV

HR- Heart Rate SV- Stroke Volume

MAP=( 2*Diastolic + Systolic)/3 MAP = CO x TPR

MAP= Mean arterial Pressure CO= Cardiac Out put TPR= Total Peripheral resistance

Blood Flow= Change Pressure/ Resistance F=P/R

F= blood flow ml/min Change Pressure P1-P2 Resistance=

Venous Return= Psf- RAP/ RVR venous return

RVR= resistance to Psf= mean systemic filling

pressure RAP= Right Atrial Pressure Mean Systemic Filling Pressure Psf= Total Volume/Total Compliance Compliance=Change Volume/ Change Pressure ml

Psf (mmHg) Total Unstressed Volume Total Compliance= ml/mmHg

Utilization Coeficient: (Art O2 – Ven 02)/Art 02

Cardiac Index: Cardiac Output/m2 of body SA Fick Principle Q= VO2 (Ca – Cv) x 100 CO=O2 absorbed by lungs (ml/min)/a-v 02 (ml/L blood)

Art O2 content = ml/ml

Q= CO(L/min)

Rate at which O2 is consumed is a function of the rate of blood flow and the rate of O2 pick up by Arterial blood. Total Blood Volume: Plasma Volume/ (1-Hct) Indicator-dilution method: V=mass/concentration Indicator Mass B= Volume B x Concentration B V1 x C1 = V2 x C2 Osmolarity: mOsm/L Osmolality: mOsm/mg Osmotic Pressure: π=CRT pressure

π= osmotic C= Concentration R= constant T=Temp

Starling Forces: Flux= Kf [Pc + πif – πp – Pif] coefcient

Kf= ultrafiltration Pc=capillary hydrostatic

pressure πif = interstitial oncotic pressure πp= plasma oncotic pressure Pif= interstitial hydrostatic pressure