Review Examination

Chapter 1

1.

A healthy individual weighs 50 kg. What is the volume of this individual’s extracellular fluid compartment?
- a.
  
  2.5 L
- b.
  
  7.5 L
- c.
  
  10.0 L
- d.
  
  20.0 L
- e.
  
  30.0 L
2.

A healthy individual loses body water from the following routes over a 24-hour period.
- Feces: 150 mL
- Expired air: 200 mL
- Perspiration: 150 mL
During this same 24-hour period, urine output is 2.5 L. How much water must this individual drink to stay in water balance?
- a.
  
  1.0 L
- b.
  
  1.5 L
- c.
  
  2.0 L
- d.
  
  2.5 L
- e.
  
  3.0 L
3.

An otherwise healthy woman develops diarrhea while on vacation in Mexico. Fecal water loss is 3 L/day. She drinks five 1-L bottles of water during this same period. If she also loses 1.5 L of water with respiration and perspiration, what is her estimated urine output over a 24-hour period?
- a.
  
  0.5 L
- b.
  
  1.0 L
- c.
  
  1.5 L
- d.
  
  2.0 L
- e.
  
  2.5 L
4.

After a rigorous practice session, on a hot afternoon, a high school football player tells the coach he feels “lightheaded” and then collapses. He is taken to the emergency department at a local hospital. Blood is drawn, and the osmolality of his plasma is 305 mOsm/kg H ₂O (normal reference range = 275 to 295 mOsm/kg H ₂O). If it could be measured, what would be the osmolality of his intracellular fluid? H int : Assume his plasma osmolality at the start of the practice session was 290 mOsm/kg H ₂O).
- a.
  
  285 mOsm/kg H ₂O
- b.
  
  290 mOsm/kg H ₂O
- c.
  
  300 mOsm/kg H ₂O
- d.
  
  305 mOsm/kg H ₂O
- e.
  
  310 mOSm/kg H ₂O
5.

A blood sample is taken from an individual whose blood osmolality is 295 mOsm/kg H ₂O. Red blood cells from this sample are then placed in the following solutions.

	Osmolality (mOsm/kg H ₂O)	σ of Solute
a. NaCl	300	1
b. Fructose	300	0.5
c. Urea	300	0
d. CaCl ₂	100	1
e. KCl	150	1

The red blood cells in which of these solutions will swell to the greatest degree?

Chapter 2

1.

Which of the following structures is a barrier to the filtration of proteins across the glomerulus?
- a.
  
  Capillary endothelial cells
- b.
  
  Basement membrane
- c.
  
  Lacis cells
- d.
  
  Parietal epithelial cells
- e.
  
  Mesangial cells
2.

The macula densa is part of which of the following structures in the kidney?
- a.
  
  Extraglomerular matrix
- b.
  
  Vasa recta
- c.
  
  Afferent arteriole
- d.
  
  Juxtamedullary nephron
- e.
  
  Juxtaglomerular apparatus
3.

The efferent arteriole of some juxtamedullary nephrons enters the renal medulla and becomes which of the following vessels?
- a.
  
  Interlobular artery
- b.
  
  Arcuate artery
- c.
  
  Vasa recta
- d.
  
  Glomerular capillary
- e.
  
  Interlobar artery
4.

The function of the vasa recta is to do which of the following?
- a.
  
  Concentrate the urine
- b.
  
  Exclude proteins from Bowman’s space
- c.
  
  Secrete renin
- d.
  
  Regulate tubuloglomerular feedback
- e.
  
  Deliver oxygen and nutrients to the renal medulla
5.

Podocin is mutated in what renal disease?
- a.
  
  Nephrotic syndrome
- b.
  
  Alport’s disease
- c.
  
  Polycystic kidney disease
- d.
  
  Nephrogenic diabetes insipidus
- e.
  
  SIADH
6.

What is the order of blood flow through the renal vasculature?
- a.
  
  Renal artery–interlobular artery–arcuate artery–interlobar artery–afferent arteriole
- b.
  
  Renal artery–interlobar artery–arcuate artery–interlobular artery–afferent arteriole
- c.
  
  Afferent arteriole–glomerular capillaries–peritubular capillary–efferent arteriole
- d.
  
  Renal artery–interlobar artery–arcuate artery–interlobular artery–peritubular capillary
- e.
  
  Renal artery–interlobar artery–arcuate artery–interlobular artery–vasa recta
7.

The renal corpuscle consists of which of the following?
- a.
  
  Afferent arteriole and glomerular capillaries
- b.
  
  Afferent arteriole, glomerular capillaries, and efferent arteriole
- c.
  
  Glomerular capillaries and Bowman’s capsule
- d.
  
  Macula densa and the juxtaglomerular apparatus
- e.
  
  Glomerular capillaries and mesangial cells
8.

Mutations in PKD1 cause polycystic kidney disease. Polycystin has what function?
- a.
  
  It transports potassium.
- b.
  
  It transports calcium.
- c.
  
  It transports water.
- d.
  
  It is an adhesion molecule.
- e.
  
  It transports sodium.
9.

The nephrotic syndrome:
- a.
  
  Is characterized by a decrease in the permeability of the glomerular capillaries to proteins
- b.
  
  Is characterized by a change in podocyte structure, including a thickening of foot processes
- c.
  
  Is characterized by a decrease in extracellular volume depletion
- d.
  
  Is characterized by an increase in the permeability of the glomerular capillaries to proteins
- e.
  
  Is caused by a decrease in renal blood flow
10.

Mesangial cells:
- a.
  
  Are specialized cells in the afferent arteriole
- b.
  
  Secrete antiinflammatory cytokines
- c.
  
  Secrete renin
- d.
  
  Are located in the renal medulla
- e.
  
  Have phagocytic activity

Chapter 3

1.

According to the tubuloglomerular feedback theory, an increase in tubular fluid NaCl concentration near the macula densa will result in which of the following?
- a.
  
  A decrease in the glomerular filtration rate of the same nephron
- b.
  
  An increase in renal blood flow to the glomerulus of the same nephron
- c.
  
  Activation of the renal sympathetic nerves
- d.
  
  An increase in proximal tubule solute and water reabsorption
- e.
  
  An increase in renin secretion
2.

Which of the following structures is a barrier to the filtration of proteins across the glomerulus?
- a.
  
  Capillary endothelial cells
- b.
  
  Podocyte slit diaphragm
- c.
  
  Lacis cells
- d.
  
  Parietal epithelial cells
- e.
  
  Mesangial cells
3.

Starling forces determine fluid movement across glomerular capillaries. What would cause an increase in the GFR?
- a.
  
  A decrease in K _f
- b.
  
  An increase in P _BS
- c.
  
  A decrease in π _GC
- d.
  
  A decrease in P _GC
- e.
  
  A decrease in πBS
4.

A 56-year-old man was admitted to the hospital with a myocardial infarction. At admission his serum creatinine was 1.2 mg/dL and his creatinine clearance was 100 mL/min. Over the next 3 days he had several periods of hypotension, and his serum creatinine increased to 3.6 mg/dL. Assuming that he is in steady-state balance for creatinine (i.e., amount excreted = amounted produced), what is his predicted creatinine clearance?
- a.
  
  10 mL/min
- b.
  
  33 mL/min
- c.
  
  50 mL/min
- d.
  
  66 mL/min
- e.
  
  100 mL/min
5.

Which of the following statements regarding the GFR is true?
- a.
  
  Plasma oncotic pressure is constant along the length of the glomerular capillary.
- b.
  
  Net filtration pressure decreases from the afferent to the efferent end of the capillary.
- c.
  
  Net filtration pressure increases from the afferent to the efferent end of the capillary.
- d.
  
  Filtration occurs at the afferent end and reabsorption at the efferent end of the capillary.
- e.
  
  Plasma oncotic pressure decreases along the length of the glomerular capillary.
6.

Which of the following responses to a fall in arterial pressure accounts for the ability of the kidneys to autoregulate GFR?
- a.
  
  Decreased resistance of the efferent arteriole
- b.
  
  Increased delivery of fluid to the end of the proximal tubule
- c.
  
  Increase resistance of the afferent arteriole
- d.
  
  Increased [NaCl] in tubular fluid at the macula densa
- e.
  
  Decreased in resistance of the afferent arteriole
7.

GFR will decrease in which of the following conditions?
- a.
  
  Dilation of the afferent arteriole
- b.
  
  Decrease in renal nerve activity
- c.
  
  Decrease in plasma oncotic pressure
- d.
  
  Increase in hydrostatic pressure in Bowman’s space
- e.
  
  Increase in renal blood flow
8.

A healthy 25-year-old woman donates a kidney to her identical twin, who has chronic renal failure. Her serum [creatinine] before removal of the kidney is 1.0 mg/dL. After donating her kidney, her serum [creatinine] increases to 2.0 mg/dL. One month later her serum [creatinine] has decreased to 1.5 mg/dL. Which of the following accounts for the fact that her serum [creatinine] fell from 2.0 to 1.5 mg/dL?
- a.
  
  Decreased production of creatinine by skeletal muscle
- b.
  
  Enhanced secretion of creatinine by the proximal tubule
- c.
  
  Increase in the GFR of each of the remaining nephrons
- d.
  
  Expansion of her ECF volume
9.

The woman described in question 8 has not modified her diet since removal of her kidney. What is the change in renal handling of Na ⁺now that she has only one kidney?

Urinary Na ⁺Excretion/24 h	Fractional Excretion of Na ⁺
a. No change	No change
b. No change	↑
c. ↑	↑
d. ↓	↓
e. ↓	↑

10.

A substance (Y) is found in the plasma at a concentration of 2 mg/dL. A 24-hour urine collection is done to determine the renal clearance of Y. The following data are obtained:
- Urine volume: 1.44 L
- Urine [Y]: 500 mg/L
What is the clearance of Y?
- a.
  
  5 mL/min
- b.
  
  25 mL/min
- c.
  
  36 mL/min
- d.
  
  100 mL/min
- e.
  
  250 mL/min
11.

Starling forces are measured across a capillary wall, and the following values are obtained:
- Capillary hydrostatic pressure: 30 mm Hg
- Capillary oncotic pressure: 25 mm Hg
- Interstitial hydrostatic pressure: 0 mm Hg
- Interstitial oncotic pressure: 15 mm Hg
If the reflection coefficient for protein across this capillary wall is 0.5, what is the pressure and direction of fluid flow across the capillary wall?

Net Pressure	Direction of Fluid Flow
a. 5 mm Hg	Into capillary
b. 10 mm Hg	Out of capillary
c. 15 mm Hg	Out of capillary
d. 20 mm Hg	Out of capillary
e. 25 mm Hg	Out of capillary

12.

Urine albumin is measured to evaluate:
- a.
  
  Acid-base status
- b.
  
  Renal disease
- c.
  
  Renal blood flow
- d.
  
  GFR
- e.
  
  The concentrating ability of the kidneys

Chapter 4

1.

A portion of Na ⁺reabsorption in the late portion of the proximal tubule is passive through the paracellular pathway. What is the primary driving force for this passive reabsorption of Na ⁺?
- a.
  
  A lower luminal than peritubular hydrostatic pressure
- b.
  
  A higher luminal than peritubular [Na ⁺]
- c.
  
  A lumen-positive transepithelial voltage
- d.
  
  A lower interstitial fluid pressure than luminal fluid oncotic pressure
2.

Na ⁺reabsorption by the thick ascending limb of Henle’s loop is:
- a.
  
  Inhibited by a decrease in peritubular capillary hydrostatic pressure
- b.
  
  Inhibited by angiotensin II
- c.
  
  Increased with increased delivered load of Na ⁺
- d.
  
  Inhibited by K ⁺-sparing diuretics
- e.
  
  Increased by natriuretic peptides
3.

Starling forces regulate sodium and water reabsorption by the proximal tubule. Which of the following changes in Starling forces would increase reabsorption?
- a.
  
  Increase in capillary hydrostatic pressure
- b.
  
  Increase in capillary oncotic pressure
- c.
  
  Decrease in capillary oncotic pressure
- d.
  
  Decrease in the permeability of the peritubular capillary to sodium and water
4.

Which of the following increases the reabsorption of sodium and chloride in the distal tubule and collecting duct?
- a.
  
  Uroguanylin
- b.
  
  Peritubular Starling forces
- c.
  
  Natriuretic peptides
- d.
  
  Aldosterone
- e.
  
  Urodilatin
5.

The tubuloglomerular feedback mechanism regulates:
- a.
  
  Blood pressure
- b.
  
  Sodium excretion
- c.
  
  GFR and RBF
- d.
  
  Potassium excretion
- e.
  
  Urine osmolality
6.

An increase in which of the following would result in a decrease in net proximal tubular fluid reabsorption?
- a.
  
  Peritubular capillary hydrostatic pressure
- b.
  
  Glomerular capillary hydrostatic pressure
- c.
  
  Renal medullary interstitial oncotic pressure
- d.
  
  Peritubular capillary oncotic pressure
- e.
  
  Filtration fraction
7.

Which hormone increases the urinary excretion of sodium and water?
- a.
  
  Epinephrine
- b.
  
  Aldosterone
- c.
  
  Angiotensin
- d.
  
  ANP
- e.
  
  Insulin
8.

The proximal tubule reabsorbs what percent of the filtered NaCl and water?
- a.
  
  100%
- b.
  
  67%
- c.
  
  50%
- d.
  
  25%
- e.
  
  10%
9.

An increase in the osmolality of the medullary interstitial fluid would directly:
- a.
  
  Stimulate urea reabsorption by the proximal tubule
- b.
  
  Stimulate sodium reabsorption by the distal tubule
- c.
  
  Stimulate water reabsorption by the descending limb of Henle’s loop
- d.
  
  Stimulate sodium reabsorption by the ascending limb of Henle’s loop
- e.
  
  Stimulate water secretion by the medullary collecting duct
10.

Normally at least 99% of the filtered load of which of the following substances is reabsorbed in the proximal tubule:
- a.
  
  Chloride
- b.
  
  Albumin
- c.
  
  Water
- d.
  
  Bicarbonate
- e.
  
  Urea

Chapter 5

1.

The daily excretion rate of total osmoles for an individual is 900 mOsm. If this individual has a urine-concentrating defect and can produce urine having a maximum osmolality of only 300 mOsm/kg H ₂O, what is the minimum volume of water that must be ingested to prevent a rise in the osmolality of the body fluids? (Assume that insensible water loss is 1.5 L/day.)
- a.
  
  1.5 L/day
- b.
  
  3.0 L/day
- c.
  
  4.5 L/day
- d.
  
  6.0 L/day
- e.
  
  7.5 L/day
2.

An individual is stricken with an illness characterized by nausea, vomiting, and diarrhea. Over a 2-day period, this individual experience a 3-kg loss in weight without a change in the plasma [Na ⁺]. What can be concluded about body fluid volumes and composition in this individual?
- a.
  
  The volume of ICF is increased
- b.
  
  The volume of the ECF is decreased
- c.
  
  The total body osmoles increased
- d.
  
  The plasma osmolality is decreased
3.

Which of the following maneuvers would be expected to stimulate AVP secretion?
- a.
  
  Infusion of 1 L hypertonic NaCl
- b.
  
  Infusion of 1 L of an isoosmotic urea solution
- c.
  
  5% expansion of the ECV
- d.
  
  Infusion of 1 L of D ₅W
- e.
  
  An acute increase in blood pressure
4.

An individual has no urine output over a 2-day period. During this time, body weight increases by 2 kg. Plasma [Na ⁺] is unchanged. What can be concluded about the volumes and composition of the body fluids?
- a.
  
  The volume of the ICF is decreased
- b.
  
  The volume of the ECF is increased
- c.
  
  The total body water is normal
- d.
  
  The plasma osmolality is decreased
5.

AVP has which of the following actions?
- a.
  
  Increases the water permeability of the thick ascending limb of Henle’s loop
- b.
  
  Increases the urea permeability of the cortical portion of the collecting duct
- c.
  
  Increases the water permeability of the collecting duct
- d.
  
  Decreases the GFR
- e.
  
  Increases the water permeability of the proximal tubule
6.

A patient has polyuria and polydipsia, and the urine osmolality is 100 mOsm/kg H ₂O. After an intravenous injection of AVP, urine volume decreases and urine osmolality increases. What is the most likely disorder in this patient?
- a.
  
  SIADH
- b.
  
  Osmotic diuresis
- c.
  
  Central diabetes insipidus
- d.
  
  Nephrogenic diabetes insipidus
- e.
  
  Nephrolithiasis (renal stone)
7.

An individual with polyuria resulting from nephrogenic diabetes insipidus is treated with a thiazide diuretic, which inhibits NaCl reabsorption by the distal tubule. After several weeks of therapy, daily urine output has decreased. What is the most likely explanation for the ability of the thiazide diuretic to reduce urine output in this individual?
- a.
  
  Stimulation of AVP secretion
- b.
  
  Decrease in ECF volume
- c.
  
  Decreased water permeability of the collecting duct
- d.
  
  Decreased expression of V ₂receptors by collecting duct cells
- e.
  
  Stimulation of NaCl reabsorption by the thick ascending limb of Henle’s loop
8.

Hyponatremia can sometimes be seen in individuals whose ECF volume is decreased by more than 10%. Which of the following factors contributes to the development of hyponatremia in this situation?
- a.
  
  Decreased levels of AVP
- b.
  
  Elevated levels of natriuretic peptides
- c.
  
  Increased excretion of Na ⁺by the kidneys
- d.
  
  Reduced excretion of solute-free water by the kidneys
- e.
  
  Development of positive Na ⁺balance
9.

A 20-year-old woman runs a marathon in 90° F weather. If she replaces all volume lost in sweat by drinking distilled water, what would happen to the volume and composition of her body fluids? ( N ote: Sweat is a hypotonic NaCl solution.)
- a.
  
  Total body water would be decreased
- b.
  
  Hematocrit would be decreased
- c.
  
  ICF volume would be decreased
- d.
  
  ECF volume would be increased
- e.
  
  Plasma osmolality would be decreased
10.

If an individual loses 2 kg of body weight in a 48-hour period, with no change in P _osm, it means that the individual has:
- a.
  
  Lost 2 kg of NaCl
- b.
  
  Lost 2 L of ECF
- c.
  
  Lost 2 kg of muscle mass
- d.
  
  Lost 2 kg of adipose tissue
- e.
  
  Hyponatremia

Chapter 6

1.

Three individuals, each weighing 55 kg and each having a plasma [Na ⁺] of 145 mEq/L, are infused with different solutions. Individual A is infused with 1 L of isotonic NaCl (290 mOsm/kg H ₂O); individual B is infused with 1 L of a mannitol solution (290 mOsm/kg H ₂O); and individual C is infused with 1 L of a 5% dextrose (D ₅W) solution (290 mOsm/kg H ₂O). Assuming that there is no urine output, and after complete equilibration of the ECF and ICF, which of these individuals will have a lower plasma [Na ⁺]?
- a.
  
  Individual A
- b.
  
  Individual B
- c.
  
  Individual C
- d.
  
  Individuals A, B, and C will have the same plasma [Na ⁺]
2.

Which of the following will occur with a decrease in the ECF volume?
- a.
  
  Increase in GFR
- b.
  
  Increase in angiotensin II levels
- c.
  
  Increase in natriuretic peptide levels
- d.
  
  Increase in free water clearance
- e.
  
  Increase in fractional excretion of Na ⁺
3.

A 56-year-old woman has congestive heart failure with generalized edema. Which of the following plays an important role in the formation of edema in this woman?
- a.
  
  Increased interstitial hydrostatic pressure
- b.
  
  Decreased interstitial oncotic pressure
- c.
  
  Increased plasma oncotic pressure
- d.
  
  Decreased renal excretion of Na ⁺
- e.
  
  Decreased venous pressure
4.

A 78-year-old woman with congestive heart failure develops pitting edema of her legs. Compared with a healthy (i.e., euvolemic) individual, what set of parameters would be expected in this woman?

Plasma Volume	ECF Volume	ECV
a. ↓	↓	↓
b. ↓	↑	↓
c. ↑	↑	↓
d. ↑	↑	↑
e. ↑	↓	↓

5.

Hyponatremia can sometimes be seen in individuals whose ECF volume is decreased by more than 10%. Which of the following factors contributes to the development of hyponatremia in this situation?
- a.
  
  Decreased levels of AVP
- b.
  
  Elevated levels of natriuretic peptides
- c.
  
  Increased excretion of Na ⁺by the kidneys
- d.
  
  Reduced excretion of solute-free water by the kidneys
- e.
  
  Development of positive Na ⁺balance
6.

A 45-year-old woman has a blood pressure of 140/90 mm Hg. Her doctor recommends a low-salt diet. What would you predict her plasma [Na ⁺] and ECF volume would be compared with their values on her previous diet? ( N ote: Assume she has reached a new steady state on her new diet.)

Plasma [Na ⁺]	ECF Volume
a. No change	↓
b. No change	No change
c. No change	↑
d. ↓	No change
e. ↓	↓

7.

A 20-year-old woman runs a marathon in 90°F weather. If she replaces all volume lost in sweat by drinking a sports drink that also contains 30 mEq/L of Na ⁺, what would happen to the volume and composition of her body fluids? ( N ote : Sweat is a hypotonic NaCl solution.)
- a.
  
  Total body water would be decreased
- b.
  
  Hematocrit would be decreased
- c.
  
  ICF volume would be decreased
- d.
  
  ECF volume would be increased
- e.
  
  Plasma osmolality would be decreased
8.

Low-pressure vascular circuit volume receptors (baroreceptors) are located in which of the following vascular structures?
- a.
  
  Aortic arch
- b.
  
  Cardiac atria
- c.
  
  Carotid sinus
- d.
  
  Juxtaglomerular apparatus of the kidney
- e.
  
  Renal veins
9.

What would be the expected neural and hormonal profile in a person whose ECF volume was decreased? ( N ote : Changes are in comparison with the euvolemic state.)

Sympathetic Nerve Activity	Aldosterone Levels	ANP Levels
a. No change	↑	↑
b. ↑	↑	↓
c. ↑	↑	No change
d. No change	↑	↓
f. ↓	↓	↑

10.

A 42-year-old woman is recovering in the hospital after removal of a benign brain tumor. She develops SIADH, and her plasma [Na ⁺] falls from 142 mEq/L to 128 mEq/L. Urine osmolality is 600 mOsm/kg H ₂O. Administration of 1 L of isotonic saline to this woman would result in which of the following changes in her plasma [Na ⁺] and urinary Na ⁺excretion?

Plasma [Na ⁺]	Urinary Na ⁺Excretion/24 h
a. No change	↑
b. ↑	↑
c. ↓	↑
d. ↑	No change
e. ↓	↓

11.

The kidneys maintain a constant plasma [Na ⁺] by regulating the excretion of what?
- a.
  
  Urea
- b.
  
  Water
- c.
  
  Creatinine
- d.
  
  Protein
- e.
  
  Albumin
12.

Hypernatremia is seen is patients with a “defect” in the ability to regulate the urinary excretion of:
- a.
  
  Sodium
- b.
  
  Potassium
- c.
  
  Urea
- d.
  
  Protein
- e.
  
  Water
13.

A patient develops gastroenteritis with vomiting and diarrhea. He is admitted to the hospital and at admission his plasma [Na ⁺] is 135 mEq/L. Over the next 2-day period he loses 2 kg of weight and his plasma [Na ⁺] decreases to 115 mEq/L. Compared with arrival in the hospital, what are the P _osmand ECF volume 2 days after admission?