RBF and GFR Flashcards
What are Tamm Horsfall protein
most abundant protein in urine, sign of stones, make in thick LoH
what would filter fastest
small and positively charged molecule
what does damaged filtration barrier cause?
larger and more negative things are getting through
what causes damaged filtration barrier
hematuria, diabetic nephropathy, minimal change disease, nephropathy
what is P_uf
capillary ultrafiltration pressure but it really is the net filtration pressure
what affects P_gc
Renal A BP, afferent arteriole resistance, efferent arteriole resistance
how do you calculate the ultrafiltration coefficient
hydraulic conductivity (L_p) x surface area (S_f)
Constricting the afferent arteriole does what for filtration pressure and GFR
decrease; decrease
constricting the efferent arteriole does what for filtration pressure and GFR
increase; increase
dilating the afferent arteriole does what for filtration pressure and GFR
increase; increase
dilating the efferent arteriole does what for filtration pressure and GFR
decrease; decrease
as O2 consumption goes up, what does Na reabsorption do
increases
what side is more affected by sympathetic
afferent; alpha 1 receptors
what are the vasoconstrictors we are looking at
- catecholamines (NE and epi)
- Ang II
- Endothelin
what vasodilators are we concerned with
- PGE 2
- PGI 2
- Nitric oxide
- Bradykinin
- Dopamine
- Atrial natriuretic peptide
what is the autoregulatory range of the kidney
80-170 mm Hg
what are the two ways that the kidneys autoregulate BP
local reflex (myogenic) physiologic feed back (juxtaglomerular cells)
myogenic feedback manifests as changes in what? what is responsible
afferent arteriole constriction and efferent arteriole dilation; Ca++
juxtaglomerular cells
secrete renin
macula densa
senses NaCl in DCT
mesangial cells
contraction
increased delivery of NaCl to macula densa does what
increases ATP (think adenosine) then vasoconstricts afferent arteriole which decreases GFR anf RBF
decreased delivery of NaCl to macula densa does what
macula densa tells JG cells to secrete renin, efferent vasoconstriction, and releases NO to afferent causing dilation
What increases the sensitivity of TGF (tubuloglomerular feedback)
- Volume contraction
- Adenosine
- PGE 2
- Thromboxane
- Ang II
what decreases sensitivity of TGF
- Volume expansion
- ANP
- NO
- cAMP
- PGI 2
- High-protein diet*
what effect does afferent vasodilation have on RBF, GFR, and peritubular capillary hydrostatic pressure
increase; increase; increase
what does afferent vasoconstriction do to RBF, GFR, and peritubular capillary hydrostatic pressure
decrease; decrease; decrease
what does efferent vasodiltion cause to RBF, GFR, and peritubular capillary hydrostatic pressure
increase, decrease, increase
what causes efferent arteriole vasodilation
sympathetics
what effect does efferent vasoconstriction have on RBF, GFR, peritubular capillary hydrostatic pressure
increase; increase or same; decrease
what causes efferent arteriole vasoconstriction
Angiotensin II
