GMS6401 Final Exam Questions With Complete Solutions, Exams of Pharmacology

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GMS6401 Final Exam Questions With Complete Solutions what is the main/primary function of the kidney ... ...Correct Answers ... ...to maintain homeostasis what does the kidney excrete ... ...Correct Answers ... ...waste products like urea drugs what does the kidney make ... ...Correct Answers ... ...-glucose (for emergencies) -ammonia -bicarbonate -arginine (an amino acid) -renin (an enzyme) -erythropoietin (hormone) -1-25 (OH)2 (form of vitamin d) (hormone) (essential for mineral metabolism) what is the role of renin ... ...Correct Answers ... ...critical for balance of sodium what is the role of erythropoietin ... ...Correct Answers ... ...acts on bone marrow to help with RBC release how many kidneys are there are what lies on top of them ... ...Correct Answers ... ...-2 -adrenal gland what is the kidneys location in the abdominal cavity ... ...Correct Answers ... ...retroperitoneal (means at back of cavity) and encased in fat (stabilizes the kidney) where do the kidneys receive blood from ... ...Correct Answers ... ...the abdominal aorta to renal artery where do kidneys send blood to ... ...Correct Answers .. . ...through the renal vein to the vena cava how many lobes make up the kidneys ... ...Correct Answers ... ...10-12 what is the outer part of the kidney called ... ...Correct Answers ... ...the cortex what is the inner part of the kidney called ... ...Correct Answers ... ...the medulla once urine leaves the medulla, what does it go through ... ...Correct Answers ... ...the minor and major calyces what is the process of voluntarily removing urine from the body called ... ...Correct Answers ... ...micturition the kidney tubules are made up of what kind of cells ... ...Correct Answers ... ...epithelial what are the two main sets of structures that make up the kidneys ... ...Correct Answers ... ...-tubules -blood vessels what are the names of the successive branches that come off the renal artery into the kidney ... ...Correct Answers ... ...-segmental arteries what part of the kidney tubules goes through the cortex, the inner and the outer medulla ... ...Correct Answers ... ...the collecting duct what makes up the distal nephron ... ...Correct Answers ... ...-distal collecting tubule -collecting duct what is the macula densa ... ...Correct Answers ... ...-where thick ascending loop of henle makes contact with the afferent arteriole as it switches to become the collecting duct -an area of communication -between tubule and blood vessel supply which type of glomeruli have long/thin loops of henle ... ...Correct Answers ... ...-glomeruli in inner cortex/juxtamedullary nephrons -are also bigger and have faster GFR what is the juxtglomerular apparatus (JGA) ... ...Correct Answers ... ...- macula densa + extraglomerular mesangium + terminal portion of afferent arteriole -allows tubules to communicate with the blood vessels that supply it where in the kidney are granular cells located ... ...Correct Answers ... ...in the afferent arteriole make renin where are the Na, K ATPases located in the kidney tubular cells ... ...Correct Answers ... ...-only on outside/peritubular surface -this allows unilateral movement of Na from lumen to peritubular capillaries to be put into blood is most of the sodium that goes through the kidney filtered or reabsorbed ... ...Correct Answers ... ...reabsorbed what is the purpose of the brush border in the proximal tubule ... ...Correct Answers ... ...to increase the surface area what parts of the tubule have lots of mitochondria ... ...Correct Answers ... ...-proximal tubule -thick ascending limb -distal convoluted tubule what are the two cells types in the collecting duct ... ...Correct Answers ... ...-principal cells (60%) -intercalated cells what part of the tubule has leaky tight junctions ... ...Correct Answers ... ...proximal tubule what part of the tubule has tight tight junctions ... ...Correct Answers ... ...ascending loop of henle what part of tubule has tight tight tight junctions ... ...Correct Answers ... ...distal nephron what type of innervation occurs in the afferent/efferent arterioles, proximal tubule, and thick ascending limb ... .. .Correct Answers ... ...sympathetic innervation using norepinephrine what are the two types of afferent/sensory nerves in the kidney ... ...Correct Answers ... ...-chemoreceptors: sensitive to composition of urine -mechanoreceptors: sensitive to degree of perfusion of renal tissue what is the primary function of the kidney ... ...Correct Answers ... ...- remove or clear substances from the blood what is the first step in urine formation ... ...Correct Answers ... ...filtration what is the normal glomerular filtration rate (GFR) in an average person ... ...Correct Answers ... ...80-200 ml/min does vary with weight what is the normal plasma volume in an average man ... ...Correct Answers ... ...3.5 L what are the specific characteristics needed for a marker substance to measure kidney function ... ...Correct Answers ... ...-freely filtered at glomerulus -not reabsorbed in tubule -not secreted in tubule -not metabolized -not toxic -no effect on kidney function rate of filtration of substance (if freely filtered) ... ...Correct Answers ... ...plasma concentration of x (Px) x GFR add the amount secreted what is fractional clearance (FC) ... ...Correct Answers .. . ...looks at how the kidney is handling the substance to how the substance is filtered FC of x = (Cx/Cin) = 1.0 Cin = clearance of inulin if FC = 1.0, this means the substance was handled exactly like inulin is what does it mean if the fractional clearance is < 1.0 ... ...Correct Answers ... ...that substance was reabsorbed to some extent what is tubular reabsorption ... ...Correct Answers ... ...the process by which valuable substances are removed from filtrate and returned to the body what is the fractional clearance of glucose ... ...Correct Answers ... ...0.0 actively reabsorbed in the proximal tubule through co-transport process with sodium what is the most common situation in which we would see glucose in the urine ... ...Correct Answers ... ...someone who has diabetes mellitus or in someone with defect in Proximal tubule (called renal glycosuria) what is the fractional clearance of phosphate ... ...Correct Answers ... ...0.2 (so, 20% of filtered phosphate will get excreted in urine) actively reabsorbed in proximal tubule reabsorptive capacity is usually exceeded and phosphate will appear in the urine what is the fractional clearance of water ... ...Correct Answers ... ...0.01 (so we excrete about 1-2 ml/min) passively reabsorbed along the nephron what is the relationship between inulin and H2O ... ...Correct Answers ... ...as water leaves the nephron, inulin does not leave so the concentration will rise how much water is filtered at the glomerulus every minute ... ...Correct Answers ... ...120 ml/min what does the urine to plasma (U/P) inulin ration tell us ... ...Correct Answers ... ...an index of the total amount of water reabsorbed, throughout the tubule, relative to what was filtered U/P = 1.0 --> no water reabsorbed U/P = 2.0 --> 50% water reabsorbed U/P = 100 --> 99% of filtered water reabsorbed what is the normal U/Pin ratio value ... ...Correct Answers ... ...between 50-100 what is free water in the body ... ...Correct Answers ... ...solute free, pure, distilled what is free water clearance ... ...Correct Answers ... ...volume of plasma cleared of pure water per minute *an exception to the general clearance formula look at how water is leaving the body relative to solute what is the free water clearance formula ... ...Correct Answers ... ...V- Cosm Cosm = normal clearance formula positive free water clearance ... ...Correct Answers ... ...-hypo-osmotic (or dilute) urine is being removed from the body -net excess amount of pure water removed negative free water clearance ... ...Correct Answers ... ...-hyperosmotic urine (concentrated) being removed from body -net gain of pure water by body due to excess removal of osmotic particles what is the fractional clearance of urea ... ...Correct Answers ... ...between 0.2 and 0.6 a waste product of protein metabolism produced by liver and excreted by kidney freely filtered, moves passively down concentration gradient not reabsorbed, but is secreted (only 10% through secretion, 90% by filtration) why can we not determine the fractional clearance of potassium ... ...Correct Answers ... ...bc its reabsorption and clearance processes are complex what are some functions of renal blood flow (RBF) in the kidney ... ...Correct Answers ... ...-glomerular filtration and tubular reabsorption/secretion -erythropoietin release -control of renin-angiotensin system -water balance what is the average weight of the kidneys in an average adult ... ...Correct Answers ... ...400 grams (less than 1% of body weight) what is the average total renal blood flow (RBF) in an average adult ... ...Correct Answers ... ...1.2 L/min (25% of cardiac output) what is the average total renal plasma flow (RPF) in an average adult ... ...Correct Answers ... ...600 ml/min (hematocrit makes up 50%) what is the average GFR in an average adult ... ...Correct Answers ... ...120 ml/min what is the formula for flow ... ...Correct Answers ... ...pressure gradient along the vessel/resistance to flow what is the main determinant of resistance ... ...Correct Answers ... ...vessel radius what is the normal starting pressure in arterioles in the capillaries ... ...Correct Answers ... ...30 mm Hg why is the pressure high at the glomerulus ... ...Correct Answers ... ...bc efferent arteriole provides back pressure what are the conduit vessels (have low resistance) in the kidneys ... ...Correct Answers ... ...-aorta -renal, segmental, interlobar, and arcuate arteries what is the first site of resistance in the kidneys ... ...Correct Answers ... ...the interlobular (cortical radial) arteries, then afferent arterioles what is the BP when it arrives in the peritubular capillaries ... ...Correct Answers ... ...20 mm HG what controls the rate of plasma flow and the BP within renal circulation ... ...Correct Answers ... ...-resistance vessels before and after the glomerulus what makes up the "ultra filtrate" of the glomerulus ... ...Correct Answers ... ...-water -low MW substances -electrolytes -urea -small peptides -NOT large proteins or blood cells what does the fractional clearance of large molecules tell us ... ...Correct Answers ... ...-an index of restriction to filtration -if FC = 1.0, means no restriction -large molecules with MW > 7,000 and a radius > 1.8 are not freely filtered in glomerulus do positively charged or negatively charged molecules get filtered more freely ... ...Correct Answers ... ...+ charged what type of molecule is used to measure glomerular restriction ... ...Correct Answers ... ...-dextran -use neutral dextran sieving curve to measure size selectivity what determines if a protein will be freely filtered or not ... ...Correct Answers ... ...size and charge of protein where is the first site of restriction for proteins in the kidney ... ...Correct Answers ... ...-the endothelial cells, which are - charged -glycocalyx, like a sticky netting -last is the glomerular basement membrane (GBM) which also has - charges what is the final barrier for large protein filtration in the glomerulus ... ...Correct Answers ... ...-podocyte slit pore and diaphragm -has specialized proteins (including nephrin) what is an example of a mutation that will allow more proteins to end up in urine ... ...Correct Answers ... ...-nephrin mutation causing congenital nephrotic syndrome -lots of protein in urine what % of filtered protein is reabsorbed ... ...Correct Answers ... ...-99% what is the most important physiologic determinant of GFR ... ...Correct Answers ... ...renal plasma flow (RPF) when RPF increases, what else changes that will cause the GFR to increase ... ...Correct Answers ... ...there is a reduction in the deltaGC (colloid osmotic rise to filtration) what happens when you increase deltaP (transcapillary hydrostatic pressure gradient) ... ...Correct Answers ... ...there will be an increase in net filtration pressure which will increase GFR by increasing FF the driving pressure out of the glomerulus will increase, so more water will be forced out of plasma what happens if there is an increase in the pressure in the bowman's space (Pbs) ... .. .Correct Answers ... ...this opposed filtration so the FF and GFR will also fall what controls the glomerular capillary pressure gradient ... ...Correct Answers ... ...the resistance tone at the afferent and efferent arterioles surrounding the glomerulus what is the glomerular capillary ultrafiltration coefficient (Kf) ... ...Correct Answers ... ...-filtration surface area (SA) and water permeability -can influence GFR -usually both very high in what situation would an increase in the distance along glomerulus affect the GFR ... ...Correct Answers ... ...-when filtration pressure is in disequilibrium oncotic pressure of the blood arriving at the glomerulus (piA) ... ...Correct Answers ... ...-changes in this pressure are inversely related to GFR control of GFR is by regulation of what: ... ...Correct Answers ... ...-RPF -the Pgc (controls hydrostatic pressure gradient) -Kf -oncotic pressure of blood arriving at glomerulus due to non filterable plasma proteins (which normally doesn't change, unless there is disease state) does relaxation of the afferent and efferent arterioles increase or decrease the RPF ... ...Correct Answers ... ...increase, because resistance has decreased if the afferent arterioles constricts, what happens to PGC and flow ... ...Correct Answers ... ...-flow decreases -PGC decreases -GFR decreases if the efferent arteriole constricts, what happens to PGC and flow ... ...Correct Answers ... ...-flow decreases -PGC increases -little change in GFR since PGC and flow are opposite if both the afferent and efferent arteriole constrict, what happens to PGC and flow ... ...Correct Answers ... ...-flow decreases -PGC does not change -GFR decreases most of the physiologic control of GFR is secondary to what... ... ...Correct Answers ... ...volume status volume depletion (low blood volume) activates what ... ...Correct Answers ... ...vasoconstrictors (and suppresses vasodilators) volume expansion (high blood volume) activates what ... ...Correct Answers ... ...vasodilators (and suppresses vasoconstrictors) what are the important "regulated" determinants of GFR ... ...Correct Answers ... ...-plasma flow -glomerular blood pressure (deltaP) -Kf -all are controlled by tone in contractile cells tone in what kind of muscle controls plasma flow and Pgc ... ...Correct Answers ... ...-vascular smooth muscle (vsm) -in afferent and efferent arterioles tone in what kind of cells determines Kf ... ...Correct Answers ... ...- glomerular mesangial cells (which are usually very relaxed) what happens when blood volume is decreased ... ...Correct Answers ... ...-decrease in activation of vasodilators -decrease in arterial BP -rapid increase in SNS by baroreceptors -rapid vasoconstriction where in the kidney is atrial natriuretic peptide (ANP or ANF) made and when is it released ... ...Correct Answers ... ...-made in cardiac atria -released in response to cardiac stretch (volume overload) what is the role of ANP in the kidney ... ...Correct Answers ... ...- vasodilator of afferent arterioles, which will increase plasma flow and then GFR -natriuretic (increases sodium excretion) how does a high dietary protein diet affect the kidneys ... ...Correct Answers ... ...-causes vasodilation of both afferent and efferent arterioles -increased RPF and GFR how does pregnancy affect the kidneys ... ...Correct Answers ... ...- vasodilation of both afferent and efferent arterioles -increased RPF and GFR how does exercise affect the kidneys ... ...Correct Answers ... ...- vasoconstriction of both afferent and efferent arterioles -deceased RPF and GFR what is renal auto regulation ... ...Correct Answers ... ...-this prevents changes in BP from changing the GFR -when BP increases, renal vascular resistance increases to keep RPF in a healthy range -only the afferent arteriole participates in this process -keeping a constant RPF and GFR during changes in BP what are the two mechanisms if auto regulation in the kidney ... ...Correct Answers ... ...-myogenic -tubuloglomerular feedback what is myogenic auto regulation ... ...Correct Answers ... ...-doesn't require nerves or hormones -happens in seconds, immediate response -general auto regulatory process -reflects inherent activity of vascular smooth muscle in response to stretch what is tubuloglomerular autoregulation feedback ... ...Correct Answers ... ...-delayed response -specific to the kidneys -happens in macula densa cells does blood pressure increase or decrease as blood flows through the two resistance vessels ... ...Correct Answers ... ...decreases to keep forward blood flow RBF supplies oxygen for what ... ...Correct Answers ... ...metabolism what process in the kidneys is the main energy requirer ... ...Correct Answers ... ...active sodium reabsorption in the tubules what tests are performed to clinically test for renal perfusion ... ...Correct Answers ... ...-doppler ultrasonography -imaging methods (contrast) when exercising, how much more blood flow is going to the working muscles ... ...Correct Answers ... ...4x in what situations is RPF higher ... ...Correct Answers .. . ...-if male -bigger size -increases with maturation -decreases with aging what is an acute kidney injury (AKI) and what causes it ... ...Correct Answers ... ...-it's an abrupt loss of kidney function due to compromised hemodynamics (failure of GFR) -due to severe systemic hypotension, intense renal vasoconstriction of afferent arteriole -always causes reductions in RPF and GFR what are the primary causes of chronic kidney disease (CKD) ... ...Correct Answers ... ...-diabetes -hypertension -immune and autoimmune diseases -can also be due elevated infrarenal angiotensin II what kind of medication actually helps slow down the progression of diabetic renal disease ... ...Correct Answers ... ...-ACE inhibitors -they lower BP are the epithelial transporting cells in the kidney symmetric or asymmetric ... ...Correct Answers ... ...asymmetric luminal membrane of kidney tubules ... ...Correct Answers ... ...-where filtrate first gets delivered -passive entry of sodium down electrochemical gradient, no sodium pumps -so, also passive Na reabsorption -also some reabsorption of glucose, amino acids, and HCO3 early proximal reabsorption favors reabsorption of what specific molecule ... ...Correct Answers ... ...HCO3- late proximal reabsorption favors reabsorption of what specific molecule ... ...Correct Answers ... ...Cl- what physiologic influences increase sodium reabsorption ... ...Correct Answers ... ...-angiotensin II -renal nerve stimulation -increased plasma oncotic pressure what physiologic influences decrease sodium reabsorption ... ...Correct Answers ... ...-ANP -NO -increased atrial BP how much sodium is reabsorbed in the thick ascending loop of henle and what drives this reabsorption ... ...Correct Answers ... ...-20- 25% -stimulated by angiotensin II -inhibited by prostaglandins what are the two active processes for sodium reabsorption in the TALH ... ...Correct Answers ... ...-Na/H exchanger -Na/K/2Cl pump -NO WATER REABSORPTION (IMPERMEABLE TO WATER) Na/K/2Cl pump ... ...Correct Answers .. . ...-sodium, potassium, and chloride are all reabsorbed into cell -some potassium gets passively diffused back out into tubule (ROMK channel) -chloride and potassium will then be pumped back into blood through a K-Cl co-transporter -sodium gets pumped back into blood through Na/K atpase that is bringing K into the cell how much sodium is reabsorbed in the distal nephron and what drives this reabsorption ... ...Correct Answers ... ...-8-10% -stimulated by aldosterone and ANG II (will increase number of Na/Cl co-transporters) -inhibited by ANP, NO -this is where the final decision is made about how much sodium should be excreted what transporters are in the distal nephron ... ...Correct Answers ... ...- Na/Cl cotransporter (thiazide sensitive) -this is the only way that sodium is able to leave the distal tubule -IMPERMEABLE TO WATER what are the two cell types in the collecting duct ... ...Correct Answers ... ...-principle cells -intercalated cells what do principle cells do in the collecting duct ... ...Correct Answers ... ...-reabsorb sodium (will make tubule lumen -) -secrete K (flowing towards - lumen) -have an "amiloride-sensitive" sodium channels (ENaC) -aldosterone stimulates ENaC to increase sodium reabsorption -the lumen will become - charged, which is what favors the secretion of K+ (electrogenic) -water permeability is variable Mannitol ... ...Correct Answers ... ...-proximal tubule diuretic -has an osmotic effect bc it cannot be reabsorbed, so it pulls water out with it Acetozolamide ... ...Correct Answers .. . ...-proximal tubule diuretic -carbonic anhydrase inhibitor Furosemide (Lasix) ... ...Correct Answers ... ...-TALH diuretic -inhibits NKCC2 transporter -most commonly used diuretic bumetanide ... ...Correct Answers ... ...-TALH diuretic -inhibits NKCC2 transporter Ethacrynic acid ... ...Correct Answers .. . ...-TALH diuretic -inhibits NKCC2 transporter thiazides ... ...Correct Answers ... ...-early distal tubule diuretic -most prescribed diuretic -inhibits NCC transporter metolazone ... ...Correct Answers ... ...-early distal tubule diuretic -inhibits NCC transporter amiloride ... ...Correct Answers ... ...-collecting duct diuretic -inhibit ENaC -K+ sparing drug what is the most important hormone of sodium balance ... ...Correct Answers ... ...aldosterone it's a mineralocorticoid in order for forward flow of blood to occur in the capillaries, does BP need to increase or decrease ... ...Correct Answers ... ...decrease what are the two antinatriuretic systems (sodium retaining) ... ...Correct Answers ... ...-renin/angiotensin/aldosterone RAAS -SNS what are the 3 natriuretic systems (sodium excretion) ... ...Correct Answers ... ...-ANP -NO -increased BP what are the main actions of aldosterone on the kidney ... ...Correct Answers ... ...-sodium retention -potassium excretion -H+ excretion what can trigger aldosterone to be released ... ...Correct Answers ... ...- increase in angiotensin II -increase in potassium concentration -decrease in sodium concentration -decrease in ANP concentration -increase in ACTH hormone hypoaldosteronism (Addison's disease) ... ...Correct Answers ... ...-sodium wasting -low ECF volume hyperaldosteronism .. . ...Correct Answers ... ...-retain sodium -high ECF volume how do alpha-adrenergic nerves play a role in sodium balance in the kidneys ... ...Correct Answers ... ...-supply blood to renal blood vessels, can cause vasoconstriction (which will increase BP) -supply renal tubules and can lead to increased sodium reabsorption how do beta adrenergic nerves play a role in sodium balance in the kidneys ... ...Correct Answers ... ...-when activated, will increase renin release from granular cells how does ANP affect sodium balance ... ...Correct Answers ... ...-released when sodium content is high in the body and causes increased right atrial pressure -has direct action on collecting duct by inhibiting sodium reabsorption -decreases aldosterone release how does NO affect sodium balance ... ...Correct Answers ... ...- production is stimulated by high salt intake -released in blood vessels and collecting duct -increases GFR -works on collecting duct to inhibit sodium reabsorption -vasodilator how do prostaglandins affect sodium balance ... ...Correct Answers ... ...- inhibit sodium reabsorption in TALH and collecting duct how does endothelin affect sodium balance ... ...Correct Answers ... ...- peptide hormone -increases sodium excretion by inhibiting sodium reabsorption in collecting duct how does pressure natriuresis affect sodium balance ... ...Correct Answers ... ...-occurs in proximal tubule -decreases luminal Na-H exchange and Na/K atpase -also causes diuresis bc sodium and water linked what is the most rapid and dramatic form of volume depletion ... ...Correct Answers ... ...hemorrhage how does the body respond to 10% or less blood loss ... . ..Correct Answers ... ...-increase SNS and RAAS to maintain normal BP how does the body respond to 10-25% blood loss ... ...Correct Answers ... ...-ADH/AVP also turned on and works as vasoconstrictor -there will still be a mild-moderate fall in BP though how does the body respond to 25% or more blood loss ... ...Correct Answers ... ...-max. activation of all vasoconstrictor systems -severe reduction in BP -reduction in organ perfusion and function (acute renal failure) -shock -body will try to increase renal sodium retention and renal water retention what causes salt-sensitive hypertension ... ...Correct Answers ... ...- increase in sodium intake will increase the blood volume and BP -baroreceptors reset to this new high BP -BP is high enough to elicit a pressure natriuresis to restore blood volume -but, high BP and increased CO lead to high organ blood flow what is the role of calcium in the body ... ...Correct Answers ... ...-major constituent of bones and teeth -nerve and muscle function -intracellular signaling molecule what is the role of phosphate in the body ... ...Correct Answers ... ...-in bones and teeth -buffering -in many macromolecules like phospholipids, phosphoproteins, and nucleic acids -enzyme activation and inactivation via phosphorylation/dephosphorylation what are the 3 main things regulating calcium in the body ... ...Correct Answers ... ...-gut -kidney -bone what is the normal plasma calcium levels ... ...Correct Answers ... ...10 mg/dL or 2.5 mM what is the normal plasma phosphate levels ... ...Correct Answers ... ...4 mg/dL how is calcitriol activated in the body ... ...Correct Answers ... ...-aka 1,25(OH)2 vitamin D -actiavted in kidney -regulated by PTH where is 99% of total body calcium found ... ...Correct Answers ... ...in ICF/bone what % of renal calcium is bound to protein ... ...Correct Answers ... ...40% what % of renal calcium is filterable ... ...Correct Answers ... ...60% mostly ionized calcium reabsorption in the proximal tubule ... ...Correct Answers ... ...- 65-70% -bulk reabsorption so not regulated -mostly passive, paracellular reabsorption -driven by sodium reabsorption calcium reabsorption in the TALH ... ...Correct Answers ... ...-20-25% -passive, paracellular -driven by lumen + transepithelial -generated by K+ reabsorption/secretion vis the NKCC2/ROMK channels -major site of regulation calcium reabsorption in the distal nephron ... ...Correct Answers ... ...-9% reabsorbed -active reabsorption, via luminal calcium channels -major site of regulation what helps increase calcium reabsorption in the TALH and distal tubule ... ...Correct Answers ... ...-PTH (most important) -calciferol/1-25 (OH)2 vitamin D -calcitonin what inhibits calcium reabsorption in the kidney ... ...Correct Answers ... ...-high plasma calcium bc it activates the calcium sensing receptor -this inhibits NKCC2 -furosemide also inhibits reabsorption what is given to people who form calcium stones ... ...Correct Answers ... ...-thiazide diuretics -they inhibit distal tubule NaCl reabsorption where is most of the phosphate in the body found ... ...Correct Answers ... ...85% is found in bone 14% is in cells less than 1% is in ECF what % of plasma phosphate is freely filtered ... ...Correct Answers ... ...90% proximal tubule phosphate reabsorption ... ...Correct Answers ... ...-80% -through secondary, active co-transport with sodium what can decrease phosphate reabsorption ... ...Correct Answers ... ...- PTH what drugs can cause hypokalemia ... ...Correct Answers ... ...-K+ wasting diuretics -beta adrenergic agonists the long term control of K balance is mainly controlled by what ... ...Correct Answers ... ...the kidney is most of the excreted K+ from the K+ that is filtered or from K+ that is secreted later in the tubule ... ...Correct Answers ... ...K+ that is secreted in the collecting duct by the principal cells most of the filtered K+ is reabsorbed in the proximal tubule or TALH what are some factors that increase K+ secretion ... ...Correct Answers ... ...-increasing intracellular K+ concentration of distal nephron cells -increasing K+ movement from cell to lumen -aldosterone (release is stimulated by increasing plasma K+) where is aldosterone made ... ...Correct Answers ... ...in the adrenal gland what would cause an increase in K+ entry on the peritubular side of the cell ... ...Correct Answers ... ...-increase in plasma K+ -increase in ECF pH how does K+ respond when the ECF becomes acidic ... ...Correct Answers ... ...K+ leaves the cell how does K+ respond when the ECF becomes basic ... ...Correct Answers ... ...K+ enters the cell how does increasing tubular fluid flow rate affect K+ ... ...Correct Answers ... ...-it reduces the amount of K+ that is in the tubules and will cause K+ to leave the cell and flow into the lumen what is the relationship between K+ filtration and K+ excretion ... ...Correct Answers ... ...since most of the K+ is reabsorbed in the proximal tubule and TALH, the K+ filtered does not have any effect on the K+ that is excreted instead, the amount of K+ that is secreted into the tubules by the principal cells ROMK channels in the collecting duct has an influence on K+ excretion how does the body respond when there is a K+ deficiency in the body ... ...Correct Answers ... ...in case of K+ emergency, the intercalated cells of the collecting duct can reabsorb some extra K+ through the H+/K+ ATPase channels total body water is what % of body weight ... ...Correct Answers ... ...60% ECF is what % of total body water ... ...Correct Answers ... ...20% ICF is what % of total body water ... ...Correct Answers ... ...40% interstitial fluid is what % of ECF ... ...Correct Answers ... ...3/4 of the ECF plasma is what % of the ECF ... ...Correct Answers ... ...1/4 of the ECF when we are truly thirsty, how does our body respond ... ...Correct Answers ... ...-central receptors in the hypothalamus are stimulated when there is a decreased volume and increased osmolality when are peripheral receptors activated to drink more water ... ...Correct Answers ... ...-dry mouth -salty/spicy food -smoking -socially -this is not actually due to dehydration what are considered some insensible losses of water ... ...Correct Answers ... ...-all unregulated -respiration -evaporation off the skin -sweating -GI tract water loss, can increase w/ vomiting or diarrhea what is the primary regulator of water output and total body water balance ... ...Correct Answers ... ...renal excretion of water what is antidiuresis ... ...Correct Answers ... ...-low water volume, concentrated (high osmolality) urine what is diuresis ... ...Correct Answers .. . ...-large volume, dilute (so low osmolality) urine what is the minimum and maximum urine flow ... ...Correct Answers ... ...-min: 0.5 L/24 hours -max: more than 24 L/24 hours is the fluid arriving in the collecting duct more or less dilute than the interstitial fluid ... ...Correct Answers ... ...more dilute water reabsorption only occurs in the collecting duct if what is present ... ...Correct Answers ... ...ADH when will urea be passively diffused out of the collecting duct ... ...Correct Answers ... ...when ADH is present there is always somewhat of a concentration gradient in the medullary interstitium due to what ... ...Correct Answers ... ...active sodium transport out of the TALH what causes the medullary interstitium concentration gradient ... ...Correct Answers ... ...-active NaCl reabsorption from thick ascending loop of henle -passive urea diffusion out of collecting duct when ADH is present what maintains the medullary interstitial concentration gradient ... ...Correct Answers ... ...-the vasa recta blood supply to the medulla is slow and a countercurrent exchanger what % of the renal blood flow goes to the cortex and through the peritubular capillaries ... ...Correct Answers ... ...85-90% what % of the renal blood flow goes through the medullary interstitium ... ...Correct Answers ... ...1% why is the countercurrent exchanger in the kidneys so important ... ...Correct Answers ... ...it maintains a gradient along the tubules what is the osmolality of the tubule fluid arriving at the descending loop of henle ... ...Correct Answers ... ...300 mosm/l what is the osmolality of the tubule fluid at the end of the thin and thick loop of henle ... ...Correct Answers ... ...200 mosm/l what is the osmolality of the tubule fluid once it enters the collecting duct ... ...Correct Answers ... ...140 mosm/l, so more dilute where does the tubule fluid go once it leaves the collecting duct and what happens to it ... ...Correct Answers ... ...-it will flow down and go through the medullary interstitium -the medullary interstitium is more concentrated than the tubule fluid so, when ADH is present, the collecting duct will be permeable to water and water will be reabsorbed passively -this can cause the final urine osmolality to rise up to 1200 mosm/l at times -if ADH is not present, there will be very little water reabsorption happening and the osmolality can drop down to 50 msom/l how are ADH and urea related ... ...Correct Answers ... ...when ADH is present, the collecting duct will be permeable to urea reabsorption how does ADH cause the collecting duct to become more permeable to water ... ...Correct Answers ... ...-it targets AQ2, which are aquaporins where is ADH made and released ... ...Correct Answers .. . ...-ADH is made in the hypothalamus in the brain -it is released by the posterior pituitary what are the different osmoreceptor neurons that have to do with ADH/AVP control ... ...Correct Answers ... ...MPO, SFO, OVLT -synapse at the PVN and SON how does ADH/AVP control osmotic homeostasis ... ...Correct Answers ... ...-when there is a lack of water, the osmoreceptors will shrink -this activates the ADH neurons -the ADH neurons project neurons to the posterior pituitary and will stimulate them to secrete ADH into the blood a what % increase in plasma osmolality triggers ADH release ... ...Correct Answers ... ...1% how is ADH triggered when there is more than a 10% loss of blood volume ... ...Correct Answers ... ...-volume baroreceptors in the carotid will sense this -this causes high amounts of ADH to be released which will also act as a vasoconstrictor what else can trigger ADH release besides changes in plasma osmolality and volume ... ...Correct Answers ... ...pain and fear what can inhibit the release of ADH ... .. .Correct Answers ... ...-alcohol -diabetes insipidus: no ADH is produced -nephrogenic diabetes insipidus: normal ADH secretion but there's a defect in the sensors or in the AQ2 what are good examples of intracellular buffers ... ...Correct Answers .. . ...-negatively charged proteins in plasma -CO3 in bones how does K+ change in response to immediate acid-base buffering ... ...Correct Answers ... ...-increase in plasma K+ and a fall in collecting duct K+ secretion and excretion what does the increase in plasma K+ during acid-base buffering trigger the release of ... ...Correct Answers ... ...aldosterone hw does an increase in HCO3 change pH ... ...Correct Answers ... ...increases pH, so less acidic how does a decreased CO2 change pH ... ...Correct Answers ... ...increases pH, so less acidic how does an increased CO2 change pH ... ...Correct Answers ... ...lowers pH, so more acidic how does a decreased HCO3 change pH ... ...Correct Answers ... ...lowers pH, so more acidic in controlling respiration, what do the central and peripheral chemoreceptors respond to ... ...Correct Answers ... ...-respond to pCO2 and pH how does respiration change when the PCO2 increases ((body becomes more acidic) ... ...Correct Answers ... ...-increase in respiration through CO2 chemoreceptors (direct stimulus) -increase respiration via reduction in plasma pH (indirect stimulus) is the Na+, H+ exchanger in the proximal tubule an indirect or direct method of reabsorption ... ...Correct Answers ... ...indirect is HCO3- filtered out or reabsorbed in the proximal tubule ... ...Correct Answers ... ...-80% is reabsorbed due to presence of carbonic anhydrase (CA) -also due to H+ secretion is HCO3- filtered out or reabsorbed in the TALH ... ...Correct Answers ... ...reabsorbed what is the role of carbonic anhydrase in the cells ... .. .Correct Answers ... ...-catalyzes conversion of water and CO2 into H2CO3 -located in lumen of proximal tubule is there usually any HCO3 in the urine ... ...Correct Answers ... ...no, usually reabsorbed -can be some in urine if there is too much HCO3 delivered to the collecting duct why is there still continued H+ secretion in the distal tubule even after all the HCO3- has been reabsorbed ... ...Correct Answers ... ...- excess H+ secretion will help create new HCO3- what are some ways that new HCO3- is made in the distal tubule ... ...Correct Answers ... ...-titratable acid helps with 1/3 (acidity comes from phosphate that escaped reabsorption ) -phosphate excretion helps with 2/3 new HCO3 where in the tubule is NH3 formed and where does it go ... ...Correct Answers ... ...-formed in proximal tubule -made from glutamine -secreted into lumen -reabsorbed in TALH -accumulates in medullary interstitium once NH3 gets trapped in the medullary interstitium, what happens to it ... ...Correct Answers ... ...-gets excreted as NH4 -every NH4 made in proximal tubule will make 1 HCO3 what is the normal pH of urine ... ...Correct Answers ... ...between 4.5-6.5 -gets more acidic as it goes through the tubule how does change in pH affect H+ secretion ... ...Correct Answers ... ...- low pH stimulates H+ secretion -high pH suppresses H+ secretion how does change in tubule volume affect H+ secretion ... ...Correct Answers ... ...-volume contraction stimulates H+ secretion -volume expansion suppresses H+ secretion what stimulates H+ secretion in the proximal tubule and TALH ... ...Correct Answers ... ...angiotensin II what stimulates H+ secretion in the distal nephron ... ...Correct Answers ... ...aldosterone at what value does proximal HCO3- become saturated ... ...Correct Answers ... ...28 meq/l how does the body compensate during metabolic alkalosis ... ...Correct Answers ... ...-immediate release of H+ buffers -reduction in respiration rate -kidneys retain H+ and excrete HCO3 simple respiratory acidosis ... ...Correct Answers ... ...-increase in PCO2 -due to depression of respiration -can also be due to barbituates or CNS tumor which will cause centrally-mediated depression of respiration -respiratory disease -neuromuscular disease how does the body compensate for respiratory acidosis ... ...Correct Answers ... ...-buffers take up some H+ (acute response, pH stays low) -no intermediate response -renal response: increased H+ secretion and increased HCO3 reabsorption (chronic response) simple respiratory alkalosis ... ...Correct Answers ... ...-decrease in PCO2 -hyperventilation: excess CO2 removed from lungs which decreases PCO2 and increases pH -high altitude -hysteria/pain (causes emotional over breathing) how does the body compensate for respiratory alkalosis ... ...Correct Answers ... ...-immediate: buffering by releasing H+ -no intermediate response -long term: renal mechanism to reduce H+ secretion, so less HCO3 reabsorption (chronic response) -w/ emotional over breathing: important to lower respiration rate or raise PCO2 by breathing expired air what is the order of response when there is a primary metabolic disturbance ... ...Correct Answers ... ...-immediate buffering -respiratory response -renal compensation what is the order of response when there is a primary respiratory disturbance ... ...Correct Answers ... ...-initial acute phase (pH is abnormal) -no intermediate response -over days kidneys will compensate where in the kidney tubule is the final decision about sodium excretion made ... ...Correct Answers .. . ...in the distal nephron Liddles syndrome ... ...Correct Answers ... ...-gain of function mutation in ENaC -there is a defect in removal from the surface membrane -this leads to high levels of ENaC expression that are not controlled by aldosterone -causes unregulated sodium reabsorption -can cause salt-sensitive hypertension -high salt suppresses plasma RAAS -can also cause hypokalemia -there will also be K+ excretion and K+ wasting what is the treatment for Liddles syndrome ... ...Correct Answers ... ...- low salt diet -amiloride what normally regulates ENaC in the kidney ... ...Correct Answers ... ...- three subunits must assemble and move into the plasma membrane -this is under control by aldosterone what is an acute kidney injury (AKI) ... ...Correct Answers ... ...-an abrupt loss of kidney function due to falls in RBF. RPF, and GFR -usually tubule damage as well what are some consequences of an acute kidney injury ... ...Correct Answers ... ...-urine flow is low (oliguria) -sometimes there is no urine flow (anuria) -if there is a reduction in sodium reabsorption, there will be an increase in urine flow (polyuria) pre-renal acute kidney injury ... ...Correct Answers ... ...-can be caused by hemorrhage -volujme depletion secondary to vomiting/diarrhea, heavy sweating, over prescription of diuretics, refusal to drink fluids -can also be caused by clamping of aorta during major surgery renal acute kidney injury ... ...Correct Answers ... ...-caused by events that happened in the kidney -toxic injury due to: drugs, heavy metals, radiocontrast, cyclosporine -endogenous toxins -rapidly progressing renal diseases what is the most common cause of renal acute kidney injury ... ...Correct Answers ... ...-ischemic damage uremia in chronic kidney disease ... ...Correct Answers .. . ...-high plasma concentration of toxic waste and -basically systemic poisoning -can cause neurological damage, platelet clotting, pericarditis, endothelial damage endothelial damage in chronic kidney disease ... ...Correct Answers ... ...- oxidative stress occurs early -hypertension develops due to endothelial dysfunction -can also cause coronary artery disease how many people in the US currently have end stage kidney disease ... ...Correct Answers ... ...500,000 how many people in US have some sort of kidney disease ... ...Correct Answers ... ...25 million 11-13% of population most people with some form of kidney disease won't reach end stage, why? ... ...Correct Answers ... ...they will die of cardiovascular events like heart attack or stroke due to endothelial dysfunction what are some traditional risk factors for renal disease ... ...Correct Answers ... ...-age -male sex -african American race -hypertension -hyperlipidemia/dyslipidemia what are some new risk factors for renal disease ... ...Correct Answers ... ...-endothelial dysfunction where does chronic kidney disease start ... ...Correct Answers ... ...-in the glomerulus what % of diabetics develop kidney disease ... ...Correct Answers ... ...30% what molecule in the kidney plays a major role in progression of renal disease ... ...Correct Answers ... ...-angiotensin II -ACE inhibitors can slow down progression bc they lower BP -constricts renal arterioles, mainly efferent arteriole -raises glomerular BP -promotes growth of mesangial cells and smooth muscle -promotes fibrosis -promotes oxidative stress what is the treatment for chronic kidney disease ... ...Correct Answers ... ...-low protein intake -drugs: ACE inhibitors (capotopril, enalapril) -blockade in thromboxanes, leukotrienes, growth factors, aldosterone -ultimate goal: to halt and reverse progression what are some changes in the aging kidney ... ...Correct Answers ... ...- decreased physiologic functions -reduced buffer -increased susceptibility to disease what are some excretory changes in the aging kidney ... ...Correct Answers ... ...-redued ability to excrete sodium, and potassium -reduced ability to conserve sodium -reduced acidification -reduced concentrating/diluting ability what are some endocrine changes in the aging kidney ... ...Correct Answers ... ...-reduced renin secretion -reduced 1-25 dihydroxy vitamin D how is response to volume contraction affected in the aging kidney ... ...Correct Answers ... ...-beta-adrenergic activity is lost -less functional JGA cells -causes lower levels of circulating renin, angiotensin II, and aldosterone how Is response to volume expansion affected in aging kidney ... ...Correct Answers ... ...-angiotensin II levels are increased -NO and PGs levels are blunted -lower natriuretic response to sodium loading what is the first line of drug treatment for hypertension in the elderly ... ...Correct Answers ... ...-diuretics -lasik used in ascending loop of henle -thiazide used in collecting duct -amiloride used in collecting duct what are some structural changes that happen to the aging kidney ... ...Correct Answers ... ...-thicker basement membrane -glomerular sclerosis -glomerular ischemia