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Renal physiology
Gross morphology of renal system
Kidney morphology
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Function of kidneys
Homeostasis
Osmoregulation
Volume regulation
Electrolyte concentration regulation
pH regulation Waste products excretion
Secretion of hormones
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Nephron
Definition
Parts
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Types of nephrons
Differences between
Number
Location
Length of loop of Henle
Capillaries accompanying
Role in function
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justamedullarynephron
cortical nephron
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Renal blood flow
Special features of renal circulation
Renal fraction
2 sets of capillaries and role of vasa recta
Efferent arteriolar lumen diameter
High pressure area
Uneven distribution
Autoregulation
Contribution for juxta glomerular apparatus
Renorenal reflex
Effect of hormones on Renal circulation
5000 ml /min1200 goes tokidney alone
blood comesthrough the
afferent arterioleand goes to theglomerularcapillary andforms the exitingefferent arteriol
thre efferentarteriole branches
off and forms theperitubularcapilliry goingdown from thecortex to themedulla next tothe juxtamedularytubules thesemake connections called vasa recta
the efferentarterioles aresmaller or thinnerthan the afferentarterioles this
causes anincrease inpressure thatpushes blooddown thepertitubelarcapilaries
we have highpressure in renalcapilaries toincrase gradientfor diffusion to
help filtration
this is the shuntof blood from onekidney to the
other in case ofinjust
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can be increasedusing dopamineandprostaglandins..so administrationof nsaids willreduceprostaglandins
and reducekidney blood flowon efferentarteriole
eman arterialblood flow
blood flow
180
60
at different
arterial pressuresbetween thisrange theglomerularfilteration staysconstant
this is anexample of autoregulation of anorgan no matterhow much wechange it doesntmodiful the flowrate
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Measurement of renal blood flow
Principle applied
Substance used
Based on the concept
we calculateusing ficksprinciple
quantity ofsubstance takenup by organ =( concentrationdiff) x bloodflowthrough organ
pah para aminohepic acid
clearance volume:-volume ofplasma losing aparticularsubstance in 1minute
so if substance xis being
secreated by theurine it must becoming out ofplasma through apassage offiltration.. as apassing throughthe ducts somesubstance might
be reabsobedand othersreadded to filtrate
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Clearance concept
Definition
Formula
Effective renal plasma flow
Extraction ratio
Total renal plasma flow
Renal blood flow
volume of plasmagetting rid of asubstance in oneminute clearance concept =
concentration of substancein urine - concentration ofsubstance in plasma Xvolune of urine formed perminute
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The following were the measurements from a healthy 33-year-oldvolunteer:
Urine Serum
Inulin 200.0 mg/dl 2.0 mg/dlGlucose 0 80.0 mg/dl
Potassium 50.0 mEq/L 5.0 mEq/L
Uric acid 15.0 mg/dl 3.0 mg/dl
PAH 100.0 mg/dl 0.2 mg/dl
Assuming that hematocrit of 50%, and urine flow of 1 ml/min, which ofthe following is the best estimate of this patients blood flow?
A. 100 ml/min
B. 200 ml/min
C. 500 ml/minD. 1000 ml/min
E. 2000 ml/min
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Factors influencing blood flow tokidney
Sympathetic stimulation
Angiotensin II
Bacterial toxins
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Glomerular filtration rate
Definition
Concept of ultra filtration
Normal value
Filtration fraction