Book: Renal Physiology

Question 1

The type of nephron responsible for renal concentration is the:

Answer 1

Juxtaglomerular

Question 2

The function of the peritubular capillaries is?

Reabsorption
Filtration
Secretion
Both A and C

Answer 2

Both A and C

Question 3

Blood flows through the nephron in the following order:

Answer 3

Afferent arteriole
Peritubular capillaries
Vasa recta
Efferent arteriole

Question 4

Filtration of protein is prevented in the glomerulus by?

Answer 4

The glomerular filtration barrier

Question 5

The renin-angiotensin-aldosterone system is responsible for all of the following except:

Vasoconstriction of the afferent arteriole
Vasoconstriction of the efferent arteriole
Reabsorbing sodium
Releasing aldosterone

Answer 5

Vasoconstriction of the afferent arteriole

Question 6

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

Answer 6

Sodium

Question 7

Secretion of renin is stimulated by:

Answer 7

Macula densa cells

Question 8

The hormone aldosterone is responsible for:

Answer 8

Sodium retention

Question 9

The fluid leaving the glomerulus has a specific
gravity of:

Answer 9

1.010

Question 10

For active transport to occur, a chemical:

Answer 10

Must combine with a carrier protein to create
electrochemical energy

Question 11

Which of the tubules is impermeable to water?

Proximal convoluted tubule
Descending loop of Henle
Ascending loop of Henle
Distal convoluted tubule

Answer 11

Ascending loop of Henle

Question 12

Glucose will appear in the urine when the:

Blood level of glucose is 200 mg/dL
Tm for glucose is reached
Renal threshold for glucose is exceeded
All of the above

Answer 12

All of the above

Question 13

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

High salt concentration in the medulla
Water-impermeable walls of the ascending loop of
Henle
Reabsorption of sodium and chloride from the
ascending loop of Henle
Reabsorption of water in the descending loop of
Henle

Answer 13

Reabsorption of water in the descending loop of
Henle

Question 14

ADH regulates the final urine concentration by controlling:

Answer 14

Tubular permeability

Question 15

Decreased production of ADH

Produces a low urine volume
Produces a high urine volume
Increases ammonia excretion
Affects active transport of sodium

Answer 15

Produces a high urine volume

Question 16

Bicarbonate ions filtered by the glomerulus are returned
to the blood:

In the proximal convoluted tubule
Combined with hydrogen ions
By tubular secretion
All of the above

Answer 16

All of the above

Question 17

If ammonia is not produced by the distal convoluted
tubule, the urine pH will be:

Answer 17

Basic

Question 18

The largest source of error in creatinine clearance tests is:

Secretion of creatinine
Improperly timed urine specimens
Refrigeration of the urine
Time of collecting blood sample

Answer 18

Improperly timed urine specimens

Question 19

Given the following information, calculate the creatinine clearance:

24-hour urine volume: 1000 mL;
serum creatinine: 2.0 mg/dL; urine creatinine: 200 mg/dL

Answer 19

69 mL/min

Question 20

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

Not filtered by the glomerulus
Completely reabsorbed by the proximal convoluted
tubule
Secreted in the distal convoluted tubule
Neither reabsorbed or secreted by the tubules

Answer 20

Neither reabsorbed or secreted by the tubules

Question 21

Performing a clearance test using radionucleotides:

A. Eliminates the need to collect urine
B. Does not require an infusion
C. Provides visualization of the filtration
D. Both A and C

Answer 21

Both A and C

Question 22

Variables that are included in the MDRD-IDSM estimated
creatinine clearance calculations include all of the
following except:

A. Serum creatinine
B. Weight
C. Age
D. Gender

Answer 22

Weight

Question 23

An advantage to using cystatin C to monitor GFR is that:

A. It does not require urine collection
B. It is not secreted by the tubules
C. It can be measured by immunoassay
D. All of the above

Answer 23

All of the above

Question 24

Solute dissolved in solvent will:

A. Raise the vapor pressure
B. Lower the boiling point
C. Decrease the osmotic pressure
D. Lower the freezing point

Answer 24

Lower the freezing point

Question 25

Substances that may interfere with freezing point measurement of urine and serum osmolarity include all of the following except: A. Ethanol B. Lactic acid C. Sodium D. Lipids

Answer 25

Sodium

Question 26

Clinical osmometers use NaCl as a reference solution because: A. 1 g molecular weight of NaCl will lower the freezing point 1.86oC B. NaCl is readily frozen C. NaCl is partially ionized similar to the composition of urine D. 1 g equivalent weight of NaCl will raise the freezing point 1.86oC

Answer 26

NaCl is partially ionized similar to the composition of urine

Question 27

The normal serum osmolarity is: A. 50 to 100 mOsm B. 275 to 300 mOsm C. 400 to 500 mOsm D. 3 times the urine osmolarity

Answer 27

275 to 300 mOsm

Question 28

After controlled fluid intake, the urine-to-serum osmolarity ratio should be at least: A. 1:1 B. 2:1 C. 3:1 D. 4:1

Answer 28

1:1

Question 29

Calculate the free water clearance from the following results: urine volume in 6 hours: 720 mL; urine osmolarity: 225mOsm; plasma osmolarity: 300mOsm

Answer 29

+0.5

Question 30

To provide an accurate measure of renal blood flow, a test substance should be completely: A. Filtered by the glomerulus B. Reabsorbed by the tubules C. Secreted when it reaches the distal convoluted tubule D. Cleared on each contact with functional renal tissue

Answer 30

Cleared on each contact with functional renal tissue

Question 31

Given the following data, calculate the effective renal plasma flow: urine volume in 2 hours: 240 mL; urine PAH: 150 mg/dL; plasma PAH: 0.5 mg/dL

Answer 31

600 mL/min

Question 32

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 acidic urine due to impaired production of ammonia D. Inability to produce an acidic urine due to increased production of ammonia

Answer 32

Inability to produce an acidic urine due to impaired production of ammonia

Question 33

Tests performed to detect renal tubular acidosis after administering an ammonium chloride load include all of the following except: A. Urine ammonia B. Arterial pH C. Urine pH D. Titratable acidity

Answer 33

Arterial pH

Question 34

A 44-year-old man diagnosed with acute tubular necrosis has a blood urea nitrogen of 60 mg/dL and a blood glucose level of 100 mg/dL. A 2+ urine glucose is also reported. State the renal threshold for glucose

Answer 34

160-mg/dL to 180-mg/dL

Question 35

34 (a) What is the significance of the positive urine glucose and normal blood glucose?

Answer 35

Renal tubular reabsorption is impaired

Question 36

A patient develops a sudden drop in blood pressure. Diagram the reactions that take place to ensure adequate blood pressure within the nephrons.

Answer 36

Juxtaglomerular apparatus → Angiotensinogen → Renin → Angiotensin I → Angiotensin II

Question 37

36 (a) When blood pressure returns to normal, how does the kidney respond?

Answer 37

Production of renin decreases and, therefore, the actions of the renin-angiotensin-aldosterone system

Question 38

A physician would like to prescribe a nephrotoxic antibiotic for a 60-year-old Caucasian man. The patient has a serum creatinine level of 1.5 mg/dL. How can the physician determine whether it is safe to prescribe this medication before the patient leaves the office?

Answer 38

The physician can calculate the approximate creatinine clearance using the MDRD-IDMS-traceable formula

Question 39

38 (a) State two additional blood tests that the physician could use to continue monitoring this patient

Answer 39

The cystatin C test beta2-microglobulin test serum tests