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57 Cards in this Set
- Front
- Back
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what is the equation for excretion
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filtration - reabsorption + secretion
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what is the Renal corpuscle
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the bowmans capsule and the glomerular capilaries
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what is the basic mechanism of urine formation
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glomerular filtration
tubular secretion tubular reabsortion |
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what is GFR
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filtration rate of all nephrons
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what are the three layers of the Glomerular capillary
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endothelium
basement membrane epithelial cells |
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what can't get filtered out of the glomerular capillaries
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things that are too big to go through the pores, proteins and stuff w/ a negative charge
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what does the hydrostatic pressure in the Glomerular and the Osmotic pressure do
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hydrostatic favors filtration
osmotic pressure favors reabsorption |
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what does the hydrostatic pressure in the bowmans capsule do
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the hydrostatic pressure favors reabosorption
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what do kidney stones do
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they raise the hydrostatic pressure in the bowmans capsule and decrease GFR because they are blocking the bowmans capsule
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what plays a critical role in the regulation of GFR
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hydrostatic pressure of the glomerular
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what are the determinants of glomerular hydrostatic pressure
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BP
Afferent arterial resistance (decreases GFR) Efferent arterial resistance (increases GFR) |
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what controls Glomerular filtration
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myogenic mechanism
macular densa feedback angiotensin 2 |
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how does the myogenic mechanism control glomerular filtration
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it blunts effect of BP on GFR by regulating blood flow
increase in BP > increase in Blood Flow > increase stretching causing release of Calcium > Ca release causes increase in resistance of the blood vessels (a.a.) going to the kidney decreasing their blood flow |
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how does the macula densa control glomerula filtration
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detects Na concentraton and sends info to e.a. and a.a.
decrease in arterial pressure decrease in hydrostatic pressure of glomerular decrease GFR macula densa senses there is less Na getting filtered via the granular cells in the afferent arteries causes the release of renin > angiotensin 2 released > efferent arteriolar resistance increases > increase in GFR OR it can decrease the afferent arteriolar resistance |
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what is juxtaglomerular apparatus
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this is the efferent arteries, afferent arteries, and the macula densa
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where is the macula densa located
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early distal tube
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what does the SNS do to constriction/resistance of the afferent arteries and efferent arteries
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increase afferent arterial resistance/constriction does the same to efferent arteries but not as much and DECREASES GFR
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what does catecholamines (norepinephrin) the do to constriction/resistance of the afferent arteries and efferent arteries
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increase afferent arterial resistance/constriction does the same to efferent arteries but not as much and DECREASES GFR
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what does the endothelin do to constriction/resistance of the afferent arteries and efferent arteries
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increase afferent arterial resistance/constriction does the same to efferent arteries but not as much and DECREASES GFR
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what does the prostaglandins do to constriction/resistance of the afferent arteries and efferent arteries
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decreases afferent arterial resistance/constriction does the same to efferent arteries too but not as much and INCREASES GFR
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what does angiotensin 2 do to glomerular filtration
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increases the resistance of efferent arteries causing an increase in GFR
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what is an EDRF
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nitric oxide
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what do EDRF do to GFR
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decreases afferent contration/resistance and efferent contration but not as much which increases GFR
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what will decrease GFR
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SNS
Catecholamines Endothelins |
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what will increase GFR
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NO (EDRF)
Angiotensin 2 Prostaglandins |
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how is stuff absorbed through the peritubular capillary
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low pressure is in the peritubular
capillaries it has transporters that allow ions etc to be reabsorbed |
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is the hydrostatic pressure in the glomerular high or low
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it is high and therefore favors filtration
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what is the equation for filter load
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GFR x plasma concentration of unbound drug
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what does filter load tell us
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it tells us how much we have absorbed
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what are the two paths fluid can be reabsorbed
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transcellular (through cells)
paracellular (between cells) |
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what occurs in primary active transport
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transport of Na is against its gradient
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what is the Na concentration in the epithelial cells
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it is low and therefore uses primary active transport to transport Na from the epithelial cells to the peritublular capillary
the Na concentration in the epithelial cells is also low to make sure that Na diffuses passively from tubule into the epithelial cell |
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what kind of diffusion does Na enter the epithelial cells
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passive/fascilitated diffusion
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what kind of diffusion does Na enter the peritubular capillaries
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primary active diffusion
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what membrane is between the epithelial cells and the interstitial fluid
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basolateral membrane (BLM)
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what membrane is between the tubule and the epithelial cells
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brush border membrane (luminal membrane)
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what occurs in 2ndary transport
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Na is going down its gradient from the tubule to the epithelial cell but
GLUCOSE/H+/AA are going against their gradients |
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where does H get pumped out
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proximal tubule
thick ascending loop |
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by the time the fluid gets to the late distal tubule what is the amount of water and Na that has been reabosorbed
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75% water already reabsorbed
97-95% Na reabsorbed |
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where does ADH act
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it works at the late distal tubule and collecting tubule
if ADH is present then H2O will be reabsorbed |
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where does aldosterone act
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it works at the late distal tubule/collecting tubule
aldosterone causes Na/H2O reabsorption and K excretion |
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what channels are at the collecting tubule
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Na and K channels
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what cells are at the collecting tubule
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principal cells
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what is the concentration of urine excreted if ADH is present
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it will be concentrated b/c a lot of the water would have been reabsorbed
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what does aldosterone stimulate
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stimulates Na channel
stimulates K channel stimulates Na/K pump |
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what does Amiloride do
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blocks re absorption of Na
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what does angiotensin 2 do to the hydrostatic pressure of perititubular capillaries
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it decreases it
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what do diuretics do to GFR
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increase it
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what do diuretics do
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block Na reabsorption
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what is the main site of action of aldosterone
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late distal tubule and collecting tubule
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what does angiotensin 2 stimulate
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it stimulates Na/K pump and Na/H pump
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what releases ADH
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pituitary gland
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how does ADH increase H2O retention
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it causes aquaporins in the epithelial cells to bind to the surface of the membrane
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what do Atrial Natriuretic peptides do
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increase GFR
decrease renin/aldosterone decrease Na reabsorption by COLLECTING DUCTS |
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what does Dopamine do
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it can act all over the tubule but mainly acts at the proximal tubule
inhibits Na/K pump and Na/H pump causes naturesis and diuresis |
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how does the SNS effect the nephrons
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it can either use norepinephrin and act on the alpha receptors in the PROXIMAL TUBULE stimulating the Na/K pump leading to sodium retention
OR it can act on the granular cells of the afferent arteries causing release of renin > angiotensin 2 > aldosterone |
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what can act on the proximal tubule
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angiotensin 2
dopamine noepinephrin |
