Deck 3: Renal Function

Question 1

Most of the sodium filtered by the glomerulus is reabsorbed in the:

A) Proximal convoluted tubule
B) Descending loop of Henle
C) Distal convoluted tubule
D) Collecting duct

Answer 1

A

Question 2

The specific gravity of the glomerular ultrafiltrate is:

A) 1.002
B) 1.010
C) 1.020
D) 1.030

Answer 2

B

Question 3

Decreased production of aldosterone:

A) Produces a low urine volume
B) Produces a high urine volume
C) Increases ammonia excretion
D) Affects active transport of sodium

Answer 3

B

Question 4

All of the following substances are reabsorbed from the glomerular filtrate by active transport except:

A) Glucose
B) Water
C) Sodium
D) Amino acids

Question 5

Aldosterone regulates sodium reabsorption in the:

A) Proximal convoluted tubule
B) Descending loop of Henle
C) Ascending loop of Henle
D) Distal convoluted tubule

Question 6

Increased production of aldosterone causes:

A) Decreased plasma sodium levels
B) Decreased glomerular blood pressure
C) Increased plasma sodium levels
D) Increased urine volume

Question 7

Production of antidiuretic hormone is controlled by the:

A) Osmotic gradient of the medulla
B) Renin-angiotensin-aldosterone system
C) State of body hydration
D) Cells of the renal cortex

Question 8

The total renal blood flow is approximately:

A) 40 mL/min
B) 120 mL/min
C) 600 mL/min
D) 1200 mL/min

Question 9

Substances removed from the blood by tubular secretion include primarily:

A) Protein, hydrogen, and ammonia
B) Protein, hydrogen, and potassium
C) Amino acids, urea, and glucose
D) Protein-bound substances, hydrogen, and potassium

Question 10

The primary chemical affected by the renin-angiotensin-aldosterone system is:

A) Glucose
B) Potassium
C) Chloride
D) Sodium

Question 11

Normal functions of the kidney include all of the following except:

A) Regulating body hydration
B) Elimination of nitrogenous wastes
C) Regulating electrolyte balance
D) Elimination of serum proteins

Question 12

The enzyme renin is produced by the kidney:

A) To activate antidiuretic hormone
B) In response to low plasma sodium levels
C) When too much sodium is being reabsorbed
D) To regulate secretion of hydrogen ions

Question 13

The order of blood flow through the nephron is:

A) Afferent arteriole, peritubular capillaries, vasa recta, efferent arteriole
B) Efferent arteriole, peritubular capillaries, vasa recta, afferent arteriole
C) Peritubular capillaries, vasa recta, afferent arteriole, efferent arteriole
D) Afferent arteriole, efferent arteriole, peritubular capillaries, vasa recta

Question 14

The osmotic gradient of the medulla:

A) Controls the permeability of the walls of the collecting duct
B) Affects passive reabsorption of water in the descending loop of Henle
C) Stimulates sodium reabsorption in the proximal convoluted tubule
D) Controls ammonia production by the distal convoluted tubule

Question 15

Water is passively reabsorbed in all parts of the nephron except the:

A) Proximal convoluted tubule
B) Descending loop of Henle
C) Ascending loop of Henle
D) Collecting duct

Question 16

Concentration of the tubular filtrate by the countercurrent mechanism is dependent on all of the following except:

A) High salt concentration in the medulla
B) Water-impermeable walls of the ascending loop of Henle
C) Reabsorption of sodium and chloride from the ascending loop of Henle
D) Active transport reabsorption of sodium and glucose in the proximal convoluted tubule

Question 17

The total renal plasma flow is approximately:

A) 60 mL/min
B) 120 mL/min
C) 600 mL/min
D) 1200 mL/min

Question 18

For active transport to occur a substance:

A) Must combine with a carrier protein to create electrochemical energy
B) Must be filtered through the proximal convoluted tubule
C) Must be in higher concentration in the filtrate than in the blood
D) Must be in higher concentration in the blood than in the filtrate

Question 19

The glomerular filtrate is described as a:

A) Plasma filtrate containing glucose and protein
B) Protein-free ultrafiltrate of plasma
C) Selective filtrate of plasma containing urea
D) Plasma filtrate without glucose and protein

Question 20

The approximate number of nephrons contained in each kidney is:

A) 100,000
B) 500,000
C) 1,000,000
D) 5,000,000

Question 21

To maintain the buffering capacity of the blood,hydrogen ions combine with:

A) Filtered phosphate ions
B) Filtered bicarbonate ions
C) Secreted ammonia
D) Secreted ammonium ions

Question 22

Performing a clearance test using radionucleotides:

A) Requires the patient to abstain from all food
B) Roes not require an infusion
C) Provides visualization of the filtration
D) Requires patient hospitalization

Question 23

In the measurement of osmolality,a solute that is dissolved in solvent will:

A) Decrease the boiling point
B) Decrease the freezing point
C) Raise the vapor pressure
D) Raise the dew point

Question 24

Measurement of urine osmolality is a more accurate measure of renal concentrating ability than specific gravity because:

A) Osmolality is measured by instrumentation
B) Specific gravity is not influenced by urea and glucose molecules
C) Osmolality is influenced equally by small and large molecules
D) Specific gravity measures only urea and glucose molecules

Question 25

The most routinely used laboratory method for measuring the glomerular filtration rate is the:

A) Inulin clearance
B) Estimated glomerular filtration rate
C) Creatinine clearance
D) Beta? microglobulin clearance

Question 26

Clearance tests used to determine the glomerular filtration rate must measure substances that are:

A) Not filtered by the glomerulus
B) Completely reabsorbed by the proximal convoluted tubule
C) Secreted in the distal convoluted tubule
D) Neither reabsorbed or secreted by the tubules

Question 27

Kidneys with impaired production of ammonia will consistently produce urine with a:

A) High pH
B) High volume
C) Low pH
D) Low volume

Question 28

To enhance the excretion of hydrogen ions,ammonia is produced by the cells of the:

A) Proximal convoluted tubule
B) Loop of Henle
C) Distal convoluted tubule
D) Collecting duct

Question 29

Results for glomerular filtration tests are reported in:

A) Milliliters per minute
B) Milliliters per 24 hours
C) Milligrams per deciliter
D) Milliequivalents per liter

Question 30

For accurate evaluation of renal tubular concentrating ability,patient preparation should include:

A) Fasting
B) Fluid deprivation
C) Increased hydration
D) Abstaining from all medications

Question 31

John White donates one of his two healthy kidneys to his twin brother.His glomerular filtration rate can be expected to:

A) Decrease by 50%
B) Increase by 50%
C) Decrease gradually over 1 year
D) Remain within a normal range

Question 32

The results of a serum osmolality performed by both freezing-point and vapor-pressure osmometry do not agree.A possible cause of this discrepancy would be:

A) Increased ethanol
B) Increased lipids
C) Decreased lactic acid
D) Decreased potassium

Question 33

A technical error that could cause a discrepancy between freezing-point and vapor-pressure osmometry readings is:

A) Failure to refrigerate the sample
B) Evaporation of the sample
C) Failure to separate cells and serum
D) Fluid deprivation of the patient

Question 34

All of the following are endogenous clearance test substances except:

A) Urea
B) Creatinine
C) Inulin
D) Beta? microglobulin

Question 35

Substances that can interfere with serum osmolality readings include all of the following except:

A) Lipids
B) Lactic acid
C) Ethanol
D) Sodium

Question 36

Performing an estimated glomerular filtration rate is helpful for determining:

A) Renal concentrating ability
B) The feasibility of administering medications
C) Early renal disease
D) Renal blood flow

Question 37

Clinical osmometers use NaCl as a reference solution because:

A) 1 g molecular weight of NaCl will lower the freezing point 1.86?C
B) NaCl is readily frozen and vaporized
C) NaCl is partially ionized similar to the composition of urine
D) 1 g equivalent weight of NaCl will lower the freezing point 1.86?C

Question 38

Calculate the creatinine clearance for a patient of average size from the following data:?Urine volume: 720 mL for 12 hours?Urine creatinine: 120 mg/dL?Serum creatinine: 1.5 mg/dL

A) 60 mL/min
B) 80 mL/min
C) 100 mL/min
D) 120 mL/min

Question 39

The renal function that is most frequently the first affected by early renal disease is:

A) Renal blood flow
B) Glomerular filtration
C) Tubular reabsorption
D) Tubular secretion

Question 40

If a substance is completely filtered by the glomerulus and then completely reabsorbed by the tubules,the clearance of that substance will be:

A) Falsely decreased
B) Falsely increased
C) Normal
D) Zero

Question 41

Following fluid deprivation,a patient has a serum osmolality of 276 mOsm and a urine osmolality of 1000 mOsm.This patient:

A) Has normal concentration ability
B) May have defective antidiuretic hormone (ADH) production
C) May have insufficient tubular ADH response
D) Has a high serum lipid concentration

Question 42

The extent to which the kidney concentrates the glomerular filtrate can be determined by measuring:

A) Serum creatinine
B) Urine creatinine
C) Serum osmolality
D) Urine and serum osmolality

Question 43

The normal serum osmolality is:

A) 50 to 100 mOsm
B) 275 to 300 mOsm
C) 400 to 500 mOsm
D) Three times urine osmolality

Question 44

Which of the following tests should be used to determine the ability of the kidneys to respond to filtrate osmolality?

A) Free water clearance
B) Fishberg test
C) Urine-to-plasma osmolality
D) p-aminohippuric acid (PAH) test

Question 45

Renal tubular acidosis can be caused by the:

A) Production of excessively acidic urine due to increased filtration of hydrogen ions
B) Production of excessively acidic urine due to increased secretion of hydrogen ions
C) Inability to produce an acid urine due to impaired production of ammonia
D) Inability to produce an acid urine due to increased production of ammonia

Question 46

Following injection of ADH,a patient has a serum osmolality of 290 mOsm and a urine osmolality of 450 mOsm.The patient:

A) Continued to observe water deprivation
B) Lacks tubular response to ADH
C) May have ingested excess alcohol
D) Should be evaluated with a creatinine clearance

Question 47

Following administration of oral ammonium chloride,a patient with renal tubular acidosis will produce:

A) Highly concentrated urine
B) Urine with a low pH
C) Urine with a high pH
D) Very dilute urine

Question 48

The serum osmolality of a patient with hyponatremia:

A) Will be similar to the urine osmolality
B) Should be greater than 300 mOsm
C) Should be lower than 275 mOsm
D) Will be falsely increased

Question 49

Which of the following tests provides information similar to specific gravity?

A) Total colloid content
B) Protein concentration
C) Absorbance
D) Osmolality

Question 50

PAH is secreted by the:

A) Proximal convoluted tubule
B) Descending loop of Henle
C) Distal convoluted tubule
D) Collecting duct

Question 51

Tests to measure the tubular secretion of hydrogen ions include all of the following except:

A) pH
B) Titratable acidity
C) Urinary bicarbonate
D) Urinary ammonia

Question 52

To provide an accurate measure of renal blood flow,a test substance should be:

A) Filtered by the glomerulus
B) Reabsorbed by the tubules
C) Secreted by the distal convoluted tubule
D) Cleared on each contact with functional renal tissues

Question 53

The PAH test is used to measure:

A) Glomerular filtration
B) Tubular reabsorption
C) Albumin excretion
D) Renal blood flow

Question 54

A free water clearance of -2.5 could be indicative of:

A) Lack of renal concentration and dilution
B) Decreased ADH production
C) Hyponatremia
D) Dehydration

Question 55

A PAH test result showing a renal plasma flow of 400 mL/min:

A) Is a normal result
B) May be falsely decreased from impaired tubular secretion
C) Should be corrected to correspond to the patient's body size
D) Indicates glomerular filtration of PAH

Question 56

To determine the amount of water that must be cleared to produce urine with the same osmolality as the ultrafiltrate,one should perform:

A) A free water clearance
B) A Mosenthal test
C) An osmolar clearance
D) A urine-to-plasma ratio

Question 57

Which of the following is not associated with the elimination of hydrogen ions?

A) Protein
B) Phosphate
C) Ammonia
D) Bicarbonate

Question 58

A patient with insufficient production of ADH would have which of the following results?

A) Urine volume-2 mL/min; osmolar clearance-2 mL/min
B) Urine volume-5 mL/min; osmolar clearance-2 mL/min
C) Urine volume-3 mL/min; osmolar clearance-4 mL/min
D) Urine volume-1 mL/min; osmolar clearance-3 mL/min

Question 59

Given the following laboratory data,calculate the free water clearance: Volume = 2800 mL/24 hour; Urine Osmo = 1200 mOsm,Plasma Osmo = 400 mOsm

A) +2 mL/min
B) +4 mL/min
C) -2 mL/min
D) -4 mL/min

Question 60

Total acidity of a urine specimen is a combination of:

A) Titratable acidity and pH
B) Titratable acidity and ammonium ion
C) pH and total acidity
D) Total acidity and ammonium ion

Question 61

Which of the following clearance substances does not require urine collection?

A) Creatinine
B) Cystatin C
C) Inulin
D) 5-HIAA

Question 62

Following a 2-hour infusion of p-aminohippuric acid (PAH),during which 200 mL of urine is collected,the urine PAH is 260 mg/dL,and the patient's plasma PAH is 0.8 mg/dL.Calculate the renal plasma volume.

A) 525 mL/min
B) 553 mL/min
C) 614 mL/min
D) 765 mL/min

Question 63

Can a patient with the following results be given a nephrotoxic medication: urine volume-720 mL/24 h,urine creatinine-100 mg/dL,and serum creatinine-2.5 mg/dL?

A) No, clearance is 20 mL/min
B) No, clearance is 40 mL/min
C) Yes, clearance is 80 mL/min
D) Yes, clearance is 120 mL/min

Question 64

A patient showing symptoms of impaired renal function has a battery of tests performed.Results are:
Serum creatinine: 2.0 mg/dL
Urine creatinine: 150 mg/dL
Serum osmolality: 270 mOsm
Urine osmolality: 100 mOsm
24-hour urine volume: 2000 mL
Based on the information provided,which renal function is abnormal in this patient?

A) Glomerular filtration
B) Tubular reabsorption
C) Tubular secretion
D) Renal blood flow

Question 65

A physician is treating a patient exhibiting symptoms of impaired renal function following a massive hemorrhage.The physician orders a serum sodium and a PAH clearance test.The patient has a serum PAH of 1.0 mg/dL,urine PAH of 200 mg/dL,and a urine volume of 240 mL in 2 hours.The serum sodium is decreased.
Using the information provided,based on the tests ordered,what renal function is the physician's primary concern?

A) Glomerular filtration
B) Tubular reabsorption
C) Tubular secretion
D) Renal blood flow

Question 66

A patient showing symptoms of impaired renal function has a battery of tests performed.Results are:
Serum creatinine: 2.0 mg/dL
Urine creatinine: 150 mg/dL
Serum osmolality: 270 mOsm
Urine osmolality: 100 mOsm
24-hour urine volume: 2000 mL
Using the information provided,calculate the creatinine clearance.

A) 50 mL/min
B) 85 mL/min
C) 105 mL/min
D) 110 mL/min

Question 67

A laboratory supervisor is authorized to purchase a new osmometer.The supervisor must decide between a freezing-point and a vapor-pressure model.
Based on the information provided,if this is a pediatric hospital,which model is better?

A) Freezing-point
B) Vapor-pressure

Question 68

A laboratory supervisor is authorized to purchase a new osmometer.The supervisor must decide between a freezing-point and a vapor-pressure model.
Using the information provided,which model is more likely to be affected by technical errors?

A) Freezing-point
B) Vapor-pressure

Question 69

Given the following information,calculate the patient's free water clearance: urine volume-360 mL in 12 hours,urine osmolality-1400 mOsm,and plasma osmolality-275 mOsm

A) +0.5 mL/min
B) -1.5 mL/min
C) -1.0 mL/min
D) -2.0 mL/min

Question 70

A 12-hour urine specimen with a volume of 360 mL is collected for a creatinine clearance.What is the volume (V)used to calculate the clearance?

A) 0.5 mL/min
B) 1.0 mL/min
C) 1.5 mL/min
D) 2.0 mL/min

Question 71

What is the physical property measured by a vapor-pressure osmometer?

A) Vapor temperature
B) Dew point temperature
C) Osmotic pressure
D) Oncotic pressure

Question 72

Given the following information,calculate the osmolar clearance: urine volume-720 mL in 24 hours,urine osmolality-700 mOsm,and plasma osmolality-300 mOsm

A) 1.0 mL/min
B) 1.2 mL/min
C) 1.8 mL/min
D) 2.0 mL/min

Question 73

A physician is treating a patient exhibiting symptoms of impaired renal function following a massive hemorrhage.The physician orders a serum sodium and a PAH clearance test.The patient has a serum PAH of 1.0 mg/dL,urine PAH of 200 mg/dL,and a urine volume of 240 mL in 2 hours.The serum sodium is decreased.
Calculate the patient's renal blood flow using the information provided.

A) 100 mL/min
B) 200 mL/min
C) 300 mL/min
D) 400 mL/min

Question 74

A laboratory supervisor is authorized to purchase a new osmometer.The supervisor must decide between a freezing-point and a vapor-pressure model.
Using the information provided,which model is affected by lipemic serum but not elevated ethanol levels?

A) Freezing-point
B) Vapor-pressure

Question 75

A laboratory supervisor is authorized to purchase a new osmometer.The supervisor must decide between a freezing-point and a vapor-pressure model.
Using the information provided,what substance is used as a reference standard in both models?

A) KCl
B) Distilled water
C) NaCl
D) Deionized water

Question 76

A patient showing symptoms of impaired renal function has a battery of tests performed.Results are:
Serum creatinine: 2.0 mg/dL
Urine creatinine: 150 mg/dL
Serum osmolality: 270 mOsm
Urine osmolality: 100 mOsm
24-hour urine volume: 2000 mL
Based on the information provided,can this patient be safely given a nephrotoxic antibiotic?

A) Yes
B) No

Question 77

A patient showing symptoms of impaired renal function has a battery of tests performed.Results are:
Serum creatinine: 2.0 mg/dL
Urine creatinine: 150 mg/dL
Serum osmolality: 270 mOsm
Urine osmolality: 100 mOsm
24-hour urine volume: 2000 mL
Based on the information provided,calculate the free water clearance.

A) -0.5
B) -1.0
C) +0.6
D) +0.9

Question 78

A patient showing symptoms of impaired renal function has a battery of tests performed.Results are:
Serum creatinine: 2.0 mg/dL
Urine creatinine: 150 mg/dL
Serum osmolality: 270 mOsm
Urine osmolality: 100 mOsm
24-hour urine volume: 2000 mL
Using the information provided,calculate the osmolar clearance.

A) 0.5
B) 1.0
C) 2.0
D) 2.5

Question 79

A patient showing symptoms of impaired renal function has a battery of tests performed.Results are:
Serum creatinine: 2.0 mg/dL
Urine creatinine: 150 mg/dL
Serum osmolality: 270 mOsm
Urine osmolality: 100 mOsm
24-hour urine volume: 2000 mL
Based on the information provided,would increasing the patient's intake of fluids alleviate this problem?

A) Yes
B) No

Question 80

Using the following values,calculate the creatinine clearance: urine volume-1200 mL/12h,urine creatinine-60 mg/dL,and serum creatinine-0.8 mg/dL

A) 60 mL/min
B) 75mL/min
C) 112 mL/min
D) 128 mL/min