Renal Practice Questions

Question 1

Which region of the nephron reabsorbs the highest percentage of filtered bicarbonate?

Accepted Answer

Proximal tubule

Answer

Collecting duct

Answer

Thick ascending limb

Answer

Distal tubule

Question 2

An investigator is studying patients with acute decompensated congestive heart failure. He takes measurements of a hormone released from atrial myocytes, as well as serial measurements of left atrial and left ventricular pressures. The investigator observes a positive correlation between left atrial pressures and the serum level of this hormone. Which of the following is most likely the mechanism of action of this hormone?

Accepted Answer

Decreases sodium reabsorption at the collecting tubules

Answer

Increases potassium excretion at the collecting ducts

Answer

Constricts afferent renal arteriole

Answer

Decreases reabsorption of bicarbonate in the proximal convoluted tubules

Answer

Increases free water reabsorption from the distal tubules

Question 3

Which factor most strongly influences protein filtration at the glomerulus?

Accepted Answer

Molecular size

Answer

Electrical charge

Answer

Shape

Answer

Temperature

Question 4

A 72-year-old female is brought to the emergency department after being found unresponsive in her garage with an open bottle of unmarked fluid. She is confused and is unable to answer questions on arrival. Her medical history is significant for Alzheimer disease, but her family says she has no medical comorbidities. Serum analysis of this patient's blood shows a pH of 7.28 with a high anion gap. The electrolyte that is most likely significantly decreased in this patient follows which of the following concentration curves across the proximal tubule of the kidney?

Accepted Answer

Curve D

Answer

Curve C

Answer

Curve E

Answer

Curve B

Answer

Curve A

Question 5

A 42-year-old man is brought to the emergency room because of confusion. His wife says he has been urinating more frequently than usual for the past 3 days. He has not had fever or dysuria. He has bipolar disorder, for which he takes lithium. His pulse is 105/min, and respirations are 14/min. He is lethargic and oriented only to person. Physical examination shows dry mucous membranes and increased capillary refill time. Laboratory studies show a serum sodium concentration of 158 mEq/L and an antidiuretic hormone (ADH) concentration of 8 pg/mL (N = 1–5). Which of the following is the most likely site of dysfunction in this patient?

Accepted Answer

Collecting duct

Answer

Hypothalamic supraoptic nucleus

Answer

Descending loop of Henle

Answer

Juxtaglomerular apparatus

Answer

Posterior pituitary gland

Question 6

To reduce the hemolysis that occurs with dialysis, researchers have developed an organic filtration membrane for dialysis that is believed to mimic the physiologic filtering apparatus of the human glomerulus. The permeability characteristics of this membrane are believed to be identical to those of the glomerular filtering membrane. Which of the following substances should be absent in the filtrate produced by this membrane?

Accepted Answer

Albumin

Answer

Amino acids

Answer

Urea

Answer

Creatinine

Answer

Sodium

Question 7

A 28-year-old male presents to his primary care physician with complaints of intermittent abdominal pain and alternating bouts of constipation and diarrhea. His medical chart is not significant for any past medical problems or prior surgeries. He is not prescribed any current medications. Which of the following questions would be the most useful next question in eliciting further history from this patient?

Accepted Answer

"Can you tell me more about the symptoms you have been experiencing?"

Answer

"Does the diarrhea typically precede the constipation, or vice-versa?"

Answer

"Is the diarrhea foul-smelling?"

Answer

"Please rate your abdominal pain on a scale of 1-10, with 10 being the worst pain of your life"

Answer

"Are the symptoms worse in the morning or at night?"

Question 8

A 70-year-old woman is brought to the emergency department due to worsening lethargy. She lives with her husband who says she has had severe diarrhea for the past few days. Examination shows a blood pressure of 85/60 mm Hg, pulse of 100/min, and temperature of 37.8°C (100.0°F). The patient is stuporous, while her skin appears dry and lacks turgor. Laboratory tests reveal:
Serum electrolytes
Sodium 144 mEq/L
Potassium 3.5 mEq/L
Chloride 115 mEq/L
Bicarbonate 19 mEq/L
Serum pH 7.3
PaO2 80 mm Hg
Pco2 38 mm Hg
This patient has which of the following acid-base disturbances?

Accepted Answer

Non-anion gap metabolic acidosis with respiratory compensation

Answer

Chronic respiratory acidosis

Answer

Anion gap metabolic acidosis with respiratory compensation

Answer

Anion gap metabolic acidosis

Answer

Non-anion gap metabolic acidosis

Question 9

An investigator studying hormone synthesis and transport uses immunocytochemical techniques to localize a carrier protein in the central nervous system of an experimental animal. The investigator finds that this protein is synthesized together with a specific hormone from a composite precursor. The protein is involved in the transport of the hormone from the supraoptic and paraventricular nuclei to its destination. The hormone transported by these carrier proteins is most likely responsible for which of the following functions?

Accepted Answer

Upregulation of renal aquaporin-2 channels

Answer

Stimulation of thyroglobulin cleavage

Answer

Hyperplasia of the adrenal zona fasciculata

Answer

Increased insulin-like growth factor 1 production

Answer

Maturation of primordial germ cells

Question 10

A 32-year-old woman is admitted to the emergency department for 36 hours of intense left-sided back pain that extends into her left groin. She reports that the pain started a day after a charitable 5 km (3.1 mi) marathon. The past medical history is relevant for multiple complaints of eye dryness and dry mouth. Physical examination is unremarkable, except for intense left-sided costovertebral pain. The results from laboratory tests are shown.
Laboratory test Result
Serum Na+ 137
Serum Cl- 110
Serum K+ 3.0
Serum creatinine (SCr) 0.82
  Arterial blood gas Result
pH 7.28
pO2 98 mm Hg
pCO2 28.5 mm Hg
SaO2% 98%
HCO3- 15 mm Hg
Which of the following explains this patient’s condition?

Accepted Answer

Decreased renal excretion of hydrogen ions (H+)

Answer

Carbonic acid accumulation

Answer

Decreased bicarbonate renal absorption

Answer

Decreased synthesis of ammonia (NH3)

Answer

Decreased excretion of nonvolatile acids

Renal

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Lessons

Questions

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Lessons

Renal blood flow distribution

Proximal tubule reabsorption

Loop of Henle function

Distal tubule and collecting duct function

Concentration and dilution of urine

Countercurrent multiplication system

Sodium handling along the nephron

Potassium balance and regulation

Calcium and phosphate handling

Magnesium handling

Water balance and osmoregulation

Diuretic mechanisms of action

Integrated nephron function

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