Renal: GFR Flashcards
(40 cards)
of all cardiac out put how much goes through both kidneys? each kidney?
of 5L, 1L in both kidneys, 500 ml in each (per min)
where are the inter vs intra lobular arteries
inter sits on top of the lobe, intra sits between the lobes
where is the arcuate artery
lies parallel on top of the lobe
where is the glomerulus
the bulbs on the ends of the afferent arterioles
where is the nephron
sticking out of the lobe, its head connects with the glomerulus
the afferent and effernt arterioles lead into where
the glomerular capillary that sits inside bowmans space
where does the glomerular capillary lie
inside bowmans space
what is PGC and what does it do
glomerular capillary pressure: pushes fluid from caps into bowmans space
what is PT and what does it do
tubular hydrostatic pressure: pushes fluid from bowmans space back into cap
what is oncotic pressure and what does it do
pressure from albumin, keeps water in the capillary space
what is the ultrafiltration coefficient and what does it do
the area available for filtration to occur (the permeability)
what is plasma flow
the continuous flow of plasma; the most important factor in the gfr
what happens to pressure of filtration as the glomerular cap length increases
ultrafiltration pressure decreases, because the long the glom cap, the lower the plasma flow at the bottom, the higher the albumin, the higher the oncotic pressure, the lower the pressure out
how to calculate single nephron gfr
permeability (kf) x ultrafiltration rate (ultrafiltration is hydrostatic pressure gradient - oncotic pressure gradient)
how does kf impact gfr
kf inc, gfr inc
how does ultrafiltration pressure impact gfr
uf inc, gfr inc
how does oncotic pressure impact gfr
onc inc, grf dec
how does plasma flow impact gfr
plasma flow inc, gfr inc
what is the most important determinant of gfr
plasma flow
how much gets filter by the glomerulus per minute? per day
100 -120 ml/min, 150-170 L/day
what determines renal blood flow
blood pressure (arterial), renal vascular pressure
what happens to the afferent arteriole if bp falls vs rises? why?
falls, AA dilates: maintain renal blood flow
rises, AA constricts, to maintain normal renal blood flow
the myogenic reflex in afferent arteriole does what
vasoconstricts and dilates the afferent arteriole
what is tubuloglomerular feedback? is it myogenic?
its feedback from the tubules that alerts the afferent arterioles to constrict under cases where you have too much salt, and want to reduce the
GFR, it is not myogenic
