MCQs
True or false? Antidiuretic hormone increases water reabsorption by increasing the permeability of the distal tubule and collecting duct to water.
true
True or false? Osmolarity of the fluid in the descending limb of the loop of Henle is greater than the osmolarity of the fluid in the ascending limb of the loop of Henle at any given level in the renal medulla.
true
U4Q1-4 Rank these structures in the order they are passed through by a molecule that is filtered from the blood by the kidney and then excreted without being reabsorbed or secreted.
1. Bowman's capsule 2. proximal tubule 3. loop of Henle 4. DCT 5. Collecting duct 6. renal papilla 7. Renal calyx 8. Renal pelvis 9. ureter 10. bladder 11. urethra
The balance of acid and base within the blood plays an important role in a number of bodily functions. How do changes in the pH of the blood affect bodily functions?
1. What is the typical blood pH range? 7.35-7.45 2. how does acidosis affect the excitability of neurons? decreases excitability 3. how does alkalosis affect the excitability of neurons? increases excitability 4. How does acidosis affect K+ levels? results in K+ retention 5. How does alkalosis affect K+ levels? 6. How does acidosis affect sympathetic activity? cardiac arrhythmias and vasodilation of blood vessels.
describe the hormonal regulation of the long-term control of blood pressure.
1. Which hormones are responsible for the long-term regulation of BP? Angiotensin II, aldosterone, ANP, ADH, and EPO 2. The regulation of which two hormones are interrelated? angiotensin II and aldosterone 3.
U4Q1-10 What are the three main Starling's forces that normally determine the net filtration pressure in the renal corpuscle?
1. hydrostatic pressure in 2.Bowman's capsule protein osmotic pressure in the plasma 3. hydrostatic pressure in glomerular capillaries
rank structures in the order a molecule of albumin would circulate through kidney
1. renal artery 2. afferent arteriole 3. glomerular capillaries 4. efferent arteriole 5. peritubular capillaries 6. renal vein
Rank these structures in the order a red blood cell would circulate through them.
1. renal artery 2. afferent arteriole 3. glomerular capillary 4. efferent arteriole 5. peritubular capillary 6. renal vein
U4Q2-13 What happens when excess H2O is ingested?
1. ↓ osmolarity 2. ↓firing osmoreceptors 3. ↓vasopressin 4. ↓H2O permeability in collecting ducts 5. ↓H2O reabsorption in collecting ducts 6. ↑ H2O excretion
Average % of the amount filtered that is reabsorbed for the 3 substances: glucose water urea
100% 99.1%? 44%
average GFR
125 ml/min = 180 L/day
U4Q1-13 If a patient produces 2 ml of urine per minute, has a plasma [Na+] of 145 mmol/L, and has a GFR of 110 ml/min, what is her filtered load for Na+ (in mmol/min).
15.95
13. An increase in the osmolality of the extracellular fluid will: A. stimulate the volume and osmoreceptors, and stimulate ADH secretion B. stimulate the volume and osmoreceptors, and inhibit ADH secretion C. inhibit the volume and osmoreceptors, and stimulate ADH secretion D. inhibit the volume and osmoreceptors, and inhibit ADH secretion E. cause no change in ADH secretion
A
About urea , all are true except: a) concentration rises in tubular fluid as the glomerular filtrate passes down the nephron. b) is actively secreted by the renal tubular cells c) concentration in the blood rises slightly after a high protein diet d) causes osmotic diuresis when its blood concentration is increased .
B
An increase in the concentration of plasma potassium causes increase in: a) release of renin b) secretion of aldosterone c) secretion of ADH d) release of natriuretic hormone e) production of angiotensin II .
B
Blood pH = 7.3, [HCO3-] is low, PCO2 is low A) respiratory alkalosis with renal compensation B) metabolic acidosis with respiratory compensation C) respiratory acidosis with renal compensation D) metabolic alkalosis with respiratory compensation
B
In controlling the synthesis and secretion of aldosterone , which of the following factors is least important ? a) renin b) angiotensin II c) concentration of plasma Na+ d) concentration of plasma K+ e) adrenocorticotropic hormone ( ACTH )
E
Neurotransmitters categorized as inhibitory would are expected to A) act independently of their receptor proteins. B) close potassium channels. C) open sodium channels. D) close chloride channels. E) hyperpolarize the membrane.
E
How does ADH affect blood pressure?
alters the reabsorption of water which occurs through the insertion of AQP2 into membrane of cells within the collecting ducts. increases number of Na+-channels in apical membrane. EPO is stimulated by a decrease in blood flow to the kidneys, which induces hypoxia within kidneys (i.e. medullary cells are always on verge of hypoxia) since RBCs make up ~45% volume of blood, any change in production will affect blood volume.
What substance is secreted by the proximal-tubule cells and prevents the pH of urine from becoming too acidic? A) bicarbonate B) salt C) glucose D) ammonia E) NaOH
ammonia
36) About the proximal convoluted tubules , all are true except : a) reabsorb most of Na+ ions in glomerular filtrate b) reabsorb most of Cl- ions in glomerular filtrate c) reabsorb most of K+ ions in glomerular filtrate d) contains JGCs which secrete renin
D
4. The plasma concentration at which a particular substance begins to appear in the urine is the: A. transport maximum (Tm) B. fractional excretion C. filtered load D. renal threshold E. titration point
D
6. Renin is produced and secreted from JG cells located in the: A. macula densa B. mesangial cells C. intercalated cells D. afferent arteriole E. interstitial cells
D
An increase in the osmolarity of the extracellular compartment will: a) stimulate the volume and osmoreceptors , and inhibit ADH secretion b) inhibit the volume and osmoreceptors , and stimulate ADH secretion . c) inhibit the volume and osmoreceptors , and inhibit ADH secretion d) stimulate the volume and osmoreceptors , and stimulate ADH secretion. e) cause no change in ADH secretion
D
The amount of potassium excreted by the kidney will decreases if : a)distal tubular flow increases b)circulating aldosterone level increase c) dietary intake of potassium increase d)Na+ reabsorption by the distal nephron decreases e) the excretion of organic ions increase .
D
The glomerular filtration rate will increase if : a) circulating blood volume increase . b) the afferent arteriolar resistance increases . c) the efferent arteriolar resistance decreases . d) the plasma protein concentration decreases .
D
What is the typical osmolarity of human blood? A) 30 mosm/L B) 100 mosm/L C) 200 mosm/L D) 300 mosm/L E) 500 mosm/L
D
which of the following regions of the nephron is impermeable to water? A) proximal tubule B) collecting duct C) distal tubule D) ascending limb of the loop of Henle E) descending limb
D
3. Co-transport of glucose: A. is equivalent to a uniport for glucose B. will not be affected if the Na+/K+ pump is blocked C. cannot move glucose against its concentration gradient D. is equivalent to an antiproton E. depends on the interaction of Na+ with the glucose carrier
E
compare and contrast steroid and peptide hormones (i.e. aldosterone and vasopressin/ADH)
Steroid hormones affect the synthesis of proteins, whereas peptide hormones affect the activity of proteins already present in the cell
The amount of H+ excreted as titratable acid bound to phosphate would be increased by all the following except : a) an increase in the amount of phosphate filtered at the glomerulus . b) an increase in the pH of the urine . c) an increase in the dietary intake of phosphate d) an increase in the level of plasma parathyroid hormone ( PTH ) e) a decrease in the renal tubular maximum (Tm) for phosphate reabsorption .
B
The glomerular filtration barrier is composed of all the following except : a) fenestrated capillary endothelium . b) macula densa . c) basement membrane . d) podocytes . e) mesangial cells .
B
U4Q2-10 Into what region of the nephron does urea secretion typically occur? A) proximal tubule B) loop of Henle C) medullary collecting duct D) cortical collecting duct E) distal convoluted tubule
B
U4Q2-15 An increase in plasma [K+] directly causes an increase in secretion of _____________. A) renin B) aldosterone C) Na+ D) ADH E) ANP
B
Which of the following acts on the hypothalamus to induce thirst? A) Aldosterone B) Angiotensin II C) ADH D) ANP E) renin
B
Which of the following substances will be more concentrated at the end of the proximal tubule than at the beginning of the proximal tubule? a) glucose . b) creatinine . c) sodium . d) bicarbonate .
B
Which one of the following statements about aldosterone is correct? a) it produces its effect by activating C-AMP . b) it produces its effect by increasing membrane permeability to potassium c) it causes an increased reabsorption of hydrogen ion. d) it has its main effect on the proximal tubule . e) it is secreted in response to an increase in blood pressure .
B
Reabsorption of Na+: a) takes place in association with CL- & HCO3 - b) occurs only in PT c) is under control of parathormone hormone d) is a passive process .
A
Which one of the following is extremely important for water conservation in mammals? A) juxtamedullary nephrons B) Bowmanʹs capsule C) urethra D) podocytes E) ureter
A
Which structure descends deep into the renal medulla only in juxtamedullary nephrons? A) loop of Henle B) collecting duct C) Bowmanʹs capsule D) proximal convoluted tubule E) glomerulus
A
____________ release is stimulated by high levels of potassium. A) Aldosterone B) Angiotensin II C) ADH D) ANP E) renin
A
Which hormone regulates the expression of Na+/K+ pumps?
aldosterone
The release of aldosterone is stimulated by:
angiotensin II
where are the potassium channels located?
apical membrane
Receptors for ADH are located in _________________
basolateral membrane of collecting duct cells.
Aquaporin-3 is located on this membrane in the absence of ADH.
cells in basolateral membrane
U4Q1-19 "Insensible water loss" is caused by:
exhalation and skin evaporation.
For a person to remain in homeostasis, the daily intake of NaCl must equal the sum of the NaCl in which three output sources? (Select all three.)
feces, sweat, urine
U4Q1-15 glucosuria
filtered load > transport maximum
filtration occurs in the _________
glomerulus
where are the receptors for aldosterone located?
in nucleus
Where are the receptors for aldosterone located?
in the cytosol of cells in the distal tubules and collecting ducts.
Potassium is exchanged for hydrogen across this membrane.
intercalated cells apical membrane
U4Q2-17 What are the two major regulators of ADH secretion?
osmoreceptors and arterial baroreceptors
The bulk of secretion occurs in the
proximal tubule
where are sodium-glucose transporters (SGLTs) located?
proximal tubule apical membrane
Most Na+ reabsorption is driven by the Na+/K+ pump located in this region. B) cells in basolateral membrane C) intercalated cells apical membrane D) proximal tubule apical membrane E) proximal tubule basolateral membrane F) intercalated cells basolateral membrane G) principal cells apical membrane.
proximal tubule basolateral membrane
where is CA located?
proximal tubule basolateral membrane
U4Q1-7 Which structures of kidney are only found in the renal cortex?
proximal tubule, JGA, renal corpuscle
U4Q2-14 Changes in K+ excretion by the kidney are mainly due to changes in K+ ________ occurring in the _______________.
secretion; cortical collecting duct
What are the effects of ANP?
↑Na+ reabsorption ↓release of ADH
U4Q1-17 Describe the micturition reflex
↑Para = detrusor contraction ↓sym = decreased internal urethral sphincter relaxation
Factors that increase K+ secretion
↓ pressure in AA and cardiac baroreceptor = ↓ renin
What would be the effects of a blockage of renin production in JG cells?
↓Angiotensin ↓Aldosterone ↓Na+ transport via distal tubule and collecting ducts ↑urine production
How does ANP decrease GFR?
↓Pgc via dilation of AA and constriction of EA
What stimulates ADH release?
↟ osmolarity within hypothalamus release of ADH modified by ↑Angiotensin II and ↓ANP
Most of the glucose that is filtered through the glomerulus undergoes reabsorption in the : a) proximal tubule b) descending limp of the loop of Henle c) ascending limb of the loop of Henle d) distal tubule e) collecting duct
A
Describe the pathway to aldosterone release
(1) Renin is released from JG cells in response to 3 different inputs (↓EA pressure, ↓filtrate Na+ and Cl- in distal tubule, and an ↑ in renal sympathetic activity originated by activation of baroreflex) (2) Which regions does aldosterone exert its effects? late distal tubule and collecting ducts.
How does Angiotensin II affect blood pressure?
(1) vasoconstrictive properties (2) altering thirst at hypothalamus (3) stimulates ADH release
U4Q2-9 Which section of the nephron is impermeable to water under all physiological circumstances? A) ascending loop of Henle B) proximal tubule C) medullary collecting duct D) descending loop of Henle E) distal convoluted tubule
A
Which of the following would contain blood in a normally functioning nephron? A) vasa recta B) Bowmanʹs capsule C) loop of Henle D) proximal tubule E) collecting duct
A
Which process in the nephron is least selective? A) filtration B) reabsorption C) active transport D) secretion E) salt pumping by the loop of Henle
A
The effect of antidiuretic hormone ( ADH ) on the kidney is to: a) increase the permeability of the distal nephron to water. b) increase the excretion of Na+ c) increase the excretion of water d) increase the diameter of the renal artery .
A
The primary renal site for the secretion of organic ions e.g urate, creatinine is: a) proximal tubule b) loop of Henle c) distal tubule d) collecting duct .
A
The hypothalamus will affect the release of ADH in response to all the following stimuli except : a) dehydration b) severe hemorrhage c) decreased blood osmolarity d) pain , anxiety , or surgical stress e) nicotine
E
15. The tonicity of the urine as it enters the renal collecting duct is: A. isotonic B. hypotonic or isotonic, but never hypertonic C. hypotonic D. hypertonic E. hypertonic or isotonic, but never hypotonic
B
Blood pH = 7.3, [HCO3-] is high, PCO2 is high. A) respiratory alkalosis with renal compensation B) metabolic acidosis with respiratory compensation C) respiratory acidosis with renal compensation D) metabolic alkalosis with respiratory compensation
C
Significant buffers for hydrogen ions generated in the body from anaerobic metabolism include all the following except: a) extracellular bicarbonate b) plasma proteins c) plasma lactate d) inorganic phosphate e) intracellular proteins
C
ADH increases the insertion of aquaporin-2 in ____________
collecting duct cells apical membrane
The greatest amount of hydrogen ion secreted by the proximal tubule is associated with: a) excretion of potassium ion b) excretion of hydrogen ion c) reabsorption of calcium ion d) reabsorption of bicarbonate ion e) reabsorption of phosphate ion
D
Which organ regulates plasma glucose concentration?
pancreas endocrine function
The majority of reabsorption occurs in the
proximal tubule
U4Q2-2 What serves as the driving force that moves amino acids from the filtrate in the proximal tubule to the cytosol of proximal tubule epithelial cells?
the concentration gradient for Na+ between the filtrate and cytosol
True or false? If glomerular filtration decreases, water excretion tends to decrease as well.
true
What are the net effects of renin on K+ secretion?
↑ aldosterone => ↑ K+ secretion
U4Q1-18 The human body is normally composed of about _________ % water by weight.
60
19. Ammonia produced by the kidneys comes mainly from: A. glutamine B. glycine C. leucine D. alanine E. B and D are correct.
A
11. The renal "countercurrent" mechanism is dependent upon the anatomic relationship between: A. the distal tubule and the macula densa B. the loop of Henle and the macula densa C. the loop of Henle and the vasa recta D. the glomerulus and the afferent and efferent arterioles E. the glomerulus and the proximal tubule
C
2. If the clearance of Substance X is greater than the clearance of inulin, it is most likely that Substance X is: A. bound to tubular proteins B. bound to plasma proteins C. secreted D. reabsorbed E. neither secreted nor reabsorbed
C
14. Polyuria (diuresis) occurs in a diabetic patient who has a GFR = 120 mL/min and a blood sugar = 350 mg/dL. This is indicative of: A. losses of water and sodium which could be prevented by administration of antidiuretic hormone (ADH) and an aldosterone-like mineralocorticoid B. diuresis due to reduced active transport of sodium out of the tubule because of diminished activity of the Na+/K+ ATPase C. a cellular and extracellular over-hydration due to water retention, caused by the glucose D. an osmotic diuresis due to glucosuria, in which water loss will exceed "salt" loss E. B and D are correct.
D
Blood pH = 7.5, [HCO3-] is high, PCO2 is high. A) respiratory alkalosis with renal compensation B) metabolic acidosis with respiratory compensation C) respiratory acidosis with renal compensation D) metabolic alkalosis with respiratory compensation
D
10. Which of the following statements is/are correct? A. Filtration fraction equals GFR divided by renal plasma flow. B. Tubular maximum secretion has a finite upper limit, though it exhibits a phenomenon analogous to the threshold phenomenon for reabsorption. C. Clearance ratio equals renal clearance of one substance divided by the clearance of another substance. D. Effective RPF is the volume of plasma flow supplied to juxtamedullary nephrons. E. A, B, and C are correct.
E
U4Q1-9 Normally, about 20% of the Na+ flowing through glomerular capillaries is filtered, while only about 10% of the Ca2+ is filtered. What accounts for this difference in filtration rate?
Half of the plasma Ca2+ is bound to plasma proteins.
Glutamine breaks down into what two products in tubular epithelial cells?
NH4+ and HCO3-
In the absence of other changes, dilation of efferent arterioles causes
a decrease in glomerular capillary hydrostatic pressure and a decrease in GFR.
U4Q2-16 Severe sweating causes _______________ in the extracellular fluid volume and ____________ in body fluid osmolarity.
a decrease; an increase
U4Q1-16 Which equation can be used to determine the glomerular filtration rate? (Note: gl = glucose, i = inulin)
(V x Ui)/Pi
20. Glomerular filtration produces an ultrafiltrate of plasma: A. in which the concentration of electrolytes is equal to plasma B. in which the concentration of protein is equal to plasma C. containing only those substances which must be eliminated in the urine D. A and B are correct. E. B and C are correct.
A
24. Which of the following does NOT contribute to the formation of maximally concentrated urine? A. active NaCl transport in the proximal convoluted tubule B. active NaCl transport in the thick ascending limb of the loop of Henle C. impermeability of the thick ascending limb of the loop of Henle to water D. high water permeability of the collecting duct due to the presence of ADH E. presence of urea in the inner medullary interstitium
A
All the following statements are true of the H+ secreted into the lumen of the distal nephron except: a)can combine with NH4+ b) can combine with HCO3 c) can combine with HPO d) can remains as free H e) is secreted by an H+-ATPase pump
A
Amino acids are almost completely reabsorbed from the glomerular filtrate via active transport in the: a) proximal tubule b) loop of Henle c) distal tubule d) collecting duct e) renal pelvis
A
Blood pH = 7.5, [HCO3-] is low, PCO2 is low. A) respiratory alkalosis with renal compensation B) metabolic acidosis with respiratory compensation C) respiratory acidosis with renal compensation D) metabolic alkalosis with respiratory compensation
A
In a laboratory experiment with three groups, one group of people drinks pure water, a second group drinks an equal amount of beer, and a third group drinks an equal amount of concentrated salt solution all during the same time period. Their urine production is monitored for several hours. At the end of the measurement period, which group will have produced the greatest volume of urine and which group the least? A) beer the most, salt solution the least B) salt solution the most, water the least C) water the most, beer the least D) beer the most, water the least E) There will be no significant difference between these groups.
A
K+ excretion is markedly influenced by: a) aldosterone b) amount of Na+ delivered to tubules c) rate of tubular secretion of H+ d) all of the above .
A
21. Which of the following is NOT a function of the kidneys? A. regulation of extracellular volume B. regulation of plasma glucose concentration C. regulation of arterial blood pressure D. excretion of the end products of protein metabolism E. excretion of foreign chemicals (e.g. pharmaceuticals, food additives, etc.)
B
5. The volume of plasma needed each minute to supply a substance at the rate at which it is excreted in the urine is known as the: A. diffusion constant of the substance B. clearance of the substance C. extraction ratio of the substance D. tubular mass of the substance E. filtration rate of the substance
B
18. The loops of Henle of the outer cortical nephrons: A. are functionally unimportant in the renal conservation of sodium and water B. do not contribute to the medullary osmotic gradient C. do not participate in the urinary diluting mechanism D. do not play an important role in overall renal function and are simply unimportant vestiges of evolutionary development E. A and C are correct.
B
20) Select the correct answer about proximal tubules: a) K+ is secreted in exchange with the Na+ which is reabsorbed under the effect of aldosterone b) glucose, amino acids & proteins are completely reabsorbed c) only 10% of the filtered water is reabsorbed d) parathormone increase phosphate reabsorption .
B
How do ADH and RAAS work together in maintaining osmoregulatory homeostasis? A) ADH monitors osmolarity of the blood and RAAS regulates blood volume. B) ADH monitors appropriate osmolarity by reabsorption of water, and RAAS maintains osmolarity by stimulating Na+ reabsorption. C) ADH an RAAS work antagonistically; ADH stimulates water reabsorption during dehydration and RAAS removal of water when it is in excess in body fluids. D) Both stimulate the adrenal gland to secrete aldosterone which increases both blood volume and pressure. E) Only when they are together in the receptor sites of proximal tubule cells, will reabsorption of essential nutrients back into the blood take place.
B
Major determinants of plasma osmolarity include all the following except: a) sodium b) hemoglobin c) chloride d) albumin e) glucose
B
Renal correction of acute hyperkalemia will result in : a) alkalosis b) acidosis c) increased secretion of HCO3- d) increased secretion of H+ e) increased secretion of Na+
B
The ability of the kidney to excrete a concentrated urine will increase if: a) the permeability of the proximal tubule to water decreases . b) the rate of blood flow through the medulla decreases c) the rate of flow through the loop of Henle increases d) the activity of the Na-K pump in the loop of Henle decreases e) the permeability of the collecting duct to water decreases
B
The volume of plasma needed each minute to supply a substance at the rate at which it is excreted in the urine is known as the : a) diffusion constant of the substance b) clearance of the substance c) extraction ratio of the substance d) tubular mass of the substance e) filtration rate of the substance
B
U4Q2-20 A patient has an arterial PCO2 of 30 mmHg and a plasma pH of 6.9. Her condition could best be described as _______________________. A) metabolic alkalosis B) metabolic acidosis C) respiratory acidosis D) respiratory alkalosis
B
U4Q2-4 Which of these solutes is NOT transported across the proximal tubule epithelium to facilitate osmotic movement of water from the proximal tubule filtrate into the surrounding renal interstitial fluid space? A) amino acids B) plasma proteins C) HCO3- D) Na+ E) glucose
B
What happens when beta cells of the pancreas release insulin into the blood? A) Blood glucose levels rise to a set point and stimulate glucagon release. B) Body cells take up more glucose. C) The liver breaks down glycogen to glucose. D) Alpha cells are stimulated to release glucose into the blood. E) Both B and D are correct.
B
When an individual is subject to short-term starvation, most available food is used to provide energy (metabolism) rather than building blocks (growth and repair). Which hormone would be particularly active in times of food shortage? A) epinephrine B) glucagon C) oxytocin D) antidiuretic hormone E) insulin
B
Which of the following activities would initiate an osmoregulatory adjustment brought about primarily through the renin-angiotensin-aldosterone system? A) sleeping B) spending several hours mowing the lawn on a hot day C) eating a bag of potato chips D) eating a pizza with olives and pepperoni E) drinking several glasses of water
B
Which of the following is not a normal response to increased blood osmolarity in humans? A) increased permeability of the collecting duct to water B) production of more dilute urine C) release of ADH by the pituitary gland D) increased thirst E) reduced urine production
B
Which of the following is secreted by the pancreas? A) ecdysone B) glucagon C) thyroxine D) oxytocin E) growth hormone
B
Which of the following stimulates aldosterone release? A) Aldosterone B) Angiotensin II C) ADH D) ANP E) renin
B
Which structure passes urine to the renal pelvis? A) loop of Henle B) collecting duct C) Bowmanʹs capsule D) proximal tubule E) glomerulus
B
_________ is activated from a precursor in the blood by two proteolytic cleavages. A) Aldosterone B) Angiotensin II C) ADH D) ANP E) renin
B
______________ activates the cAMP second messenger system in principal cells of the distal tubules and collecting ducts. A) Aldosterone B) Angiotensin II C) ADH D) ANP E) renin
C
_______________ increases water reabsorption by inserting aquaporin-2 proteins into the apical membrane of collecting duct cells. A) Aldosterone B) Angiotensin II C) ADH D) ANP E) renin
C
16. Which of the following might you expect to find associated with chronic renal failure? A. elevated packed cell volume (hematocrit) B. abnormally low plasma creatinine concentration C. decreased bone density D. lower than normal PTH (parathyroid hormone) concentration E. None of the above is correct.
C
8. A 100 kg man has a plasma osmolarity of 300 mOsM (milliosmolar). After he drinks 2 liters of water (and before any fluid losses) his steady-state plasma osmolarity would be approximately: A. 270 mOsM B. 280 mOsM C. 290 mOsM D. 300 mOsM E. 321 mOsM
C
9. The normal human glomerular filtration rate (GFR) is approximately (in mL/min): A. 25 B. 50 C. 125 D. 300 E. 500
C
Ammonia is an affective important urinary buffer for which of the following reasons : a) its production in the kidney decrease during chronic acidosis b) the walls of the renal tubules are impermeable to NH3 c) the walls of the renal tubules are impermeable to NH4+ d) its acid base reaction has a low pKa e) none of the above .
C
H+ secretion in the distal nephron is enhanced by all the following except: a) an increase in the level of plasma aldosterone b) an increase in the tubular luminal concentration of poorly reabsorbable anions c) hyperkalemia d) metabolic acidosis e) respiratory acidosis
C
In the presence of ADH, The distal nephron is least permeable to : a) water . b) ammonia . c) urea . d) sodium . e) carbon dioxide.
C
More hydrogen is secreted in : a) alkalosis b) administration of diamox c) hypokalemia d) hyperventilation.
C
Processing of filtrate in the proximal and distal tubules accomplishes what important function? A) sorting plasma proteins according to size B) converting toxic ammonia to less toxic urea C) maintaining a constant pH in body fluids D) regulating the speed of blood flow through the nephron E) reabsorbing urea to maintain osmotic balance
C
Proper functioning of the human kidney requires considerable active transport of sodium in the kidney tubules. If these active transport mechanisms were to stop completely, how would urine production be affected? A) No urine would be produced. B) A less-than-normal volume of hypoosmotic urine would be produced. C) A greater-than-normal volume of isoosmotic urine would be produced. D) A greater-than-normal volume of hyperosmotic urine would be produced. E) A less-than-normal volume of isoosmotic urine would be produced.
C
Urinary volume is increased by all the following except : a) diabetes insipidus b) diabetes mellitus c) sympathetic stimulation d) increased renal arterial pressure e) infusion of mannitol
C
What is unique about transport epithelial cells in the ascending loop of Henle in humans? A) They are the largest epithelial cells in the body. B) They are not in contact with interstitial fluid. C) Their membranes are impermeable to water. D) 50% of their cell mass is comprised of smooth endoplasmic reticulum. E) They are not affected by high levels of nitrogenous wastes.
C
What would account for increased urine production as a result of drinking alcoholic beverages? A) increased aldosterone production B) increased blood pressure C) inhibition of antidiuretic hormone secretion (ADH) D) increased reabsorption of water in the proximal tubule E) the osmoregulator cells of the brain increasing their activity
C
When a person is dehydrated, hypotonic fluid will be found in the: a) glomerular filtrate b) proximal tubule c) loop of Henle d) distal convoluted tubule e) collecting duct
C
Which of the following limits the volume of the obligatory water loss? A) diameter of the loop of Henle B) the osmolarity at the early portion of the distal tubule C) the maximal osmolarity of the medullary osmotic gradient D) the water permeability of the the collecting ducts E) the water permeability of the distal tubule
C
17. The vasa recta: A. are the straight portions of the proximal tubules, found just proximal to the loops of Henle B. extend from the efferent arterioles of the superficial cortical nephrons C. are the microvilli found on the cells of the macula densa D. comprise the capillary network found in the medulla of the kidney E. are the small straight segments of afferent arterioles found directly next to the macula densa
D
23. Which of the following is NOT a function of the kidneys? A. regulation of extracellular osmolality B. regulation of acid-base balance C. excretion of end-products of muscle metabolism D. activation of antidiuretic hormone E. activation of vitamin D
D
Carbonic anhydrase plays an important role in all the following except: a) the renal handing of HCO3- within the cells of the proximal tubule . b) the renal handling of HCO3- within the lumen of proximal tubule . c) the renal handling of HCO3- within the cells of the tubules of the distal nephron d) the renal handling of HCO3 - within the lumen of the tubules of the distal nephron e) gastric secretion of HCl by parietal cells.
D
Extracellular bicarbonate ions serve as an effective buffer for all the following except : a) sulfuric acid b) phosphate acid c) lactic acid d) carbonic acid e) ß- hydroxybutyric acid
D
Glomerular filtration rate would be increased by: a) constriction of the afferent arteriole b) a decrease in afferent arteriolar pressure c) compression of the renal capsule d) a decrease in the concentration of plasma protein e) a decrease in renal blood flow
D
How does ADH function at the cellular level? A) ADH stimulates the reabsorption of glucose through channel proteins. B) It triggers the synthesis of an enzyme that makes the phospholipid bilayer more permeable to water. C) It causes membranes to include more phospholipids that have unsaturated fatty acids. D) It causes an increase in the number of aquaporins in the apical membranes of collecting duct cells. E) It decreases the speed at which filtrate flow through the nephron leading to increased reabsorption of water.
D
In the distal tubules, sodium reabsorption is increased directly by increased: a) sympathetic nerve stimulation of the kidney . b) atrial natriuretic hormone secretion . c) antidiuretic hormone secretion . d) aldosterone secretion e) angiotensin secretion .
D
U4Q2-18 Which of the following is NOT an example of a nonvolatile acid? A) lactic acid B) sulfuric acid C) phosphoric acid D) carbonic acid
D
U4Q2-6 A patient's blood sample shows that plasma osmolarity is 380 mOsm/L (normal = 300) and he is forming a large volume of urine with an osmolarity of 80 mOsm/L (normal 600-900). Intranasal administration of antidiuretic hormone (ADH) causes no change in his condition. What disease state does he have? A) osmotic diuresis B) diabetes mellitus C) central diabetes insipidus D) nephrogenic diabetes insipidus
D
Where is the macula densa located? A) proximal tubule B) ascending loop of Henle C) descending loop of Henle D) distal convoluted tubule
D
Which of the following processes of osmoregulation by the kidney is the least selective? A) salt pumping to control osmolarity B) H+ pumping to control pH C) reabsorption D) filtration E) secretion
D
Which one of the following, if present in a urine sample, would likely be caused by trauma? A) amino acids B) glucose C) salts D) erythrocytes E) vitamins
D
If a person drinks a large amount of water in a short period of time, he or she may die from water toxicity. ADH can help prevent water retention through interaction with target cells in the A) anterior pituitary. B) posterior pituitary.term-23 C) adrenal gland. D) bladder. E) kidney
E
1. For those substances that are actively reabsorbed, the maximal amount that can be transported per unit time by the kidney tubules: A. depends on the maximum rate at which the transport mechanism itself operates B. is directly related to the plasma concentration of the substance C. is termed the tubular transport maximum D. is dependent upon tubular load E. A and C are correct.
E
22. Which of the following does NOT contribute to titratable acid when found in the urine? A. H2PO4- B. lactic acid C. beta-hydroxybutyric acid D. acetoacetic acid E. NH4+
E
7. About 4 to 6 days after you place a normal person on a low-sodium diet, which of the following will be observed? A. plasma renin and aldosterone are below normal B. plasma renin and aldosterone are above normal C. plasma sodium concentration is below normal D. plasma sodium concentration is normal E. B and D are correct.
E
Blood samples taken from an individual who had been fasting for 24 hours would have which of the following? A) high levels of insulin B) high levels of glucagon C) low levels of insulin D) low levels of glucagon E) both B and C
E
The high osmolarity of the renal medulla is maintained by all of the following except A) diffusion of salt from the thin segment of the ascending limb of the loop of Henle. B) active transport of salt from the upper region of the ascending limb. C) the spatial arrangement of juxtamedullary nephrons. D) diffusion of urea from the collecting duct. E) diffusion of salt from the descending limb of the loop of Henle.
E
U4Q2-1 In a normally-hydrated person, about two thirds of filtered water and Na+ is reabsorbed in the __________. A) collecting duct B) DCT C) Loop of Henle D) peritubular capillaries E) proximal tubule
E
U4Q2-12 When the mean arterial blood pressure falls below normal, which of these is part of the reflex response that brings it back toward normal? A) ↑ANP B) ↓angiotensin II C) ↑firing by parasympathetic nerves D) ↓renin E) ↑aldosterone
E
Which structure increases the reabsorption of Na+ when stimulated by aldosterone? A) loop of Henle B) collecting duct C) Bowmanʹs capsule D) proximal tubule E) distal tubules
E
U4Q1-8 Which equation correctly relates the basic renal processes for a substance that is neither produced or destroyed by the kidney?
E+R = F+S
RENAL HANDLING OF POTASSIUM
K+ is reabsorbed and secreted. 1. describe K+ reabsorption moves into tubular epithelial cells via basolateral Na+/K+ pumps (move K+ into cell). ↑ intracellular K+ = ↑K+ movement through basolateral K+ channels into peritubular fluid. NET MOVEMENT OF K+ = outward into peritubular fluid NET MOVEMENT OF K+ = inward into distal tubule and collecting ducts
SODIUM REABSORPTION
The JG cells within the afferent arterioles respond to a decrease in pressure and a decrease in Na+ or Cl- within the distal tubules (through macula densa) by increasing the secretion of renin. Renin is an enzyme that converts angiotensinogen (secreted by liver) into Angiotensin I ACE is an enzyme that converts angiotensin I into angiotensin II, present in capillary endothelium. Aldosterone binds to its receptor which causes an increase in the open state of Na+ channels in apical membrane as well as an increase in their synthesis. ANP secretion release is stimulated by an increase in atrial stretch (due to increase in atrial pressure). What are the ways Na+ reabsorption is facilitated? (1) aldosterone ---> An increase in number of active Na+/K+ pumps in the basolateral membrane and sodium channels in apical membrane increase movement of Na+ out of filtrate. (2) vasoconstriction of AA that is initated by Angiotensin II, which ↓GFR and allows more time for Na+ reabsorption. (3) ANP has opposite effect of aldosterone. Induces a decrease in Na+ reabsorption by ↓ EA resistance through dilation and decreasing the number of open Na+ channels in apical membrane (↓ Na+ reabsorption). ↑ANP = ↓renin and ↓aldosterone.
Aldosterone increases the number of potassium channels in ______________
collecting duct cells apical membrane
U4Q2-7 To calculate the "obligatory water loss," you divide the _________________ by the ___________________________.
daily excreted solute load; maximum urinary concentration
describe how K+ is reabsorbed in the proximal tubule
diffuses through leaky tight junctions in proximal tubular epithelial cells, just like urea
where are the JG cells located?
in walls of afferent arterioles
hypervolemia
increase in plasma volume
U4Q2-5 The collecting duct is permeable to water only when the hormone _________ causes proteins called __________ to be inserted into the ____________ membrane of tubular epithelial cells
vasopressin, aquaporins, apical
What increases excretion of Na+?
↑GFR ↓Na+ reabsorption in cortical collecting duct ↑Aldosterone ↑ANP