renal physio Flashcards
renal blood flow is ____of cardiac output
20%
plasma in the glomerular capillaries must pass thru (3)
- capillary endothelium
- basement membrane
- bowman’s capsule epithelium
incr glomerular permeability to large proteins is the problem indicated in
nephrotic syndrome
nephrons that have glomeruli located in the outer cortex and short loop of henle
cortical nephrons
nephrons that have glomeruli located deep in cortex and long loop of henle
juxtamedullary nephrons
which type of nephron has a long loop of henle
juxtamedullary nephrons
name for the specialized peritubular capillaries surrounding juxtamedullary nephrons
vasa recta
net filtration pressure is defined by?
- hydrostatic forces
2. colloid osmotic forces
net filtration pressure= ____-____-_____
glomerular hydrostatic pressure-bowman’s capsule pressure-glomerular oncotic pressure
most sodium reabsorption happens at what level in the nephron?
proximal tubule
most amino acids are reabsorbed at what level?
proximal tubule
most glu reabsorbed at what level?
proximal tubule
60-70% potassium reabsorbed where?
proximal tubule
what percent of K is excreted
12%
HCO3 is ____into the tubules and H+ is _____into the tubular lumen
filtered; secreted
lumen of proximal tubule is ____osmotic
isoosmotic
lumen of thick ascending loop of henle is ____osmotic
hypoosmotic
the kidney fxns to form urine that is ____-concentratrated than plasma
more
what serves as the counter current exchanger?
vasa recta
levels of regulation of reabsorption & secretion (3)
- local control (auto-reg)
- hormonal control
- nervous control
method of auto-regulation in kidneys
tubuloglomerular feedback
3 mechanisms of renin regulation
- baroreceptor (pressure in afferent arteriole)
- beta adrenergic stimulation of renin
- macula dense (incr NaCl)
aldosterone acts on the___
cortical collecting tubules
the renal clearance of a substance is the ______that is completely cleared of the substance by the kidney per unit time
completely cleared of the substance
what is the best overall index of kidney fxn?
GFR
relationship of GFR to renal plasma flow?
GFR = RPF x FF
sudden decr in kidney fxn
acute kidney injury
AKI that results from kidney hypoperfusion
pre-renal cause
AKI that occurs from urinary tract obstruction
post renal cause (ie. stones
when do clinical sx manifest in chronic kidney disease
when fxnal nephron is 70-75% below normal
