PHYS 2 Renal Blood flow and glomerular filtration rate Flashcards
forces causing filtration by the glomerular capillaries?
favoring filtration
opposing filtration
formulas and how to determine net fluid filtration, no net movement, and net fluid reabsorption
Three physical factors contribute to GFR
GFR=
Ultrafiltration pressure (formula)
what can alter PUF?
what determines PGC
ultrafiltration coefficient
whats the formula?
what influences Kf?
what change SA/permeability?
glomerular mesangial cells?
hydrostatic pressures in renal vasculature
where do we see sharp declines
where is there an interesting plateau?
Ultrafiltration pressure along the glomerular capillary from afferent to efferent arteriole.
we lose fluid and cant lose larger proteins and such so the oncotic pressur in glomerular capillaries increases while the hydrostatic pressure decreases due to resistance of flow
different combinations of constricting and dilating afferent and efferent arterioles will have what effect on GFR and RBF?
Renal blood flow
kidney vs brain oxygen consumption
in kidney O2 consumption related to?
physiological control of glomerular filtration and RBF
intrinsic vs extrinsic control mechanism for renal hemodynamics
sympathetic exert what on renal blood vessels?
what receptors?
vasoconstrictors?
vasodilators?
Glomerulotubular balance
Autoregulation
maintains what?
what two things will help with this?
autoregulatory range
80-170 mmHg
Local myogenic feedback reflex
Tubuloglomerular feedback
what senses what?
what is maintained?
Tubuloglomerular feedback
in case of increased renal perfusion presssure/
When the GFR increases and causes the NaCl concentration of tubular fluid at the macula densa to rise, more NaCl enters macula densa cells. This process leads to an increase in the formation and release of adenosine triphosphate (ATP) and adenosine, a metabolite of ATP, by macula densa cells, which causes vasoconstriction of the afferent arteriole. Vasoconstriction of the afferent arteriole returns the GFR to normal levels
tubuloglomerular feedback
in the case of decreased renal perfusion pressure
afferent?
efferent?
mediated by?
when the GFR and NaCl concentration of tubule fluid decrease, less NaCl enters macula densa cells, and the production and release of ATP and adenosine decline. The decrease in ATP and adenosine causes vasodilation of the afferent arteriole, which returns the GFR to normal
increase sensitivity of TGF?
decrease?
