Renal - Amboss

Question 1

Amboss Renal

How do you calculate an anion gap?

Answer 1

Anion gap = Na⁺ + K⁺ - (Cl⁻ + HCO₃⁻)

Question 2

Amboss Renal

How can renal plasma flow be estimated using PAH?

Answer 2

RPF = (U_PAH * Urine flow rate) / P_PAH

Question 3

Amboss Renal

After calculating renal plasma flow (U_PAH * urine flow rate / P_PAH), how can you figure out what the total renal blood flow is?

Answer 3

RBF = RPF / (1 - hematocrit)

Question 4

Amboss Renal

If you calculate the renal blood flow in a healthy individual, how can you determine cardiac output?

Answer 4

CO = Renal blood flow / 0.2

(The kidneys get 20 - 25% of cardiac output.)

Question 5

Amboss Renal

Treatment is initiated in a patient with prostate cancer. Initially, there is an increase in serum testosterone and DHT, followed by a sustained decrease in both serum hormone levels.

He is being treated with what?

Answer 5

Leuprolide

(flutamide would result in a chronically elevated serum testosterone)

(finasteride would result in an elevated serum testosterone but no increase in DHT)

Question 6

Amboss Renal

Whether sporadic or familial, renal cell carcinomas have an association with deletions in which gene?

Answer 6

VHL

Question 7

Amboss Renal

A patient presents with fever, flank pain, hematuria, and a maculopapular rash. Urinalysis shows eosinophilia, WBCs and RBCs. He reports frequent meloxicam use over the past two weeks for back pain.

Kidney biopsy will likely show interstitial infiltration of what cell type?

Answer 7

T cells

Question 8

Amboss Renal

A patient presents with fever, flank pain, hematuria, and a maculopapular rash. Urinalysis shows eosinophilia, WBCs and RBCs. He reports frequent meloxicam use over the past two weeks for back pain.

Is this renal papillary necrosis?

Answer 8

No, this is allergic interstitial nephritis.

RPN usually results from chronic analgesic use; eosinophilia and maculopapular rash are inconsistent with RPN.

Question 9

Amboss Renal

Which medication types are contraindicated in patients with bilateral renal artery stenosis?

(Why?)

Answer 9

ACE inhibitors; ARBs

(inhibition of efferent arteriole constriction –> decreased GFR)

Question 10

Amboss Renal

A patient presents with a benign tumor in the superior pole of the kidney. Histology shows epithelial cells characterized by an excessive amount of mitochondria, resulting in an abundant acidophilic, granular cytoplasm.

What is the likely diagnosis?

Answer 10

Oncocytoma

Note: the large, eosinophilic, granular cells in the image are called ‘oncocytes.’

Question 11

Amboss Renal

The uremia seen in ESRD is associated with what changes (if any) in pH, serum bicarbonate, anion gap, and pCO₂?

Answer 11

Anion-gap metabolic acidosis

(low pH, low HCO₃^-, mildly low pCO₂ — a buildup of acids leads to the pH, bicarb, and anion-gap changes and a subsequent respiratory compensation)

Question 12

Amboss Renal

A normal GFR is in about what range?

Answer 12

90 - 125 mL/min

Question 13

Amboss Renal

Urothelial cancers are strongly linked with exposure to what compound(s)?

Answer 13

Aromatic amines (e.g. benzidine - (rubber production, oil refineries, dye-making, etc.), nicotine, arsenic, cisplatin (and other platinum chemotherapeutics), cyclophosphamide

Question 14

Amboss Renal

As ACE inhibitors cause a dilation of the efferent arteriole, what effect do they have on GFR, renal plasma flow, and filtration fraction?

Answer 14

GFR - decreased

RPF - increased

FF - decreased

Question 15

Amboss Renal

What is the earliest diagnostic sign of diabetic nephropathy?

Answer 15

Microalbuminuria

Question 16

Amboss Renal

What are the two major signs of Goodpasture syndrome?

Answer 16

Hematuria + hemoptysis

(+ other signs of nephritic syndrome)

Question 17

Amboss Renal

True/False.

Hematuria and hemoptysis are the major signs of granulomatosis with polyangiitis.

Answer 17

False.

Hematuria and hemoptysis are the major signs of Goodpasture syndrome.

Granulomatosis with polyangiitis is initially associated with rhinosinusitis, otitis media, ocular lesions, mucocutaneous granulomas, and vasculitic purpura.

Question 18

Amboss Renal

Goodpasture syndrome is caused by what main etiology?

Answer 18

Anti-GBM antibodies

Question 19

Amboss Renal

Crescents in Bowman’s space (due to fibrin-deposition) are associated with which generic cause of nephritic syndrome?

Answer 19

Rapidly progressive glomerulonephritis

Question 20

Amboss Renal

Which diuretic category is calcium-sparing?

Answer 20

Thiazides

Question 21

Amboss Renal

Why are serum lipids elevated in nephrotic syndrome?

Answer 21

Secondary to the hypoalbuminemia

(hepatic lipoprotein synthesis increases to maintain oncotic pressure)

Question 22

Amboss Renal

What disorder is associated with recurrent UTIs, bilateral flank masses, hypertension, and elevated serum creatinine?

Answer 22

ADPKD

Question 23

Amboss Renal

A patient with sudden, possibly painful urges to urinate followed by frequent, small-volume voids likely has what condition?

What is the cause?

Answer 23

Urge incontinence;

detrusor muscle spasms

Question 24

Amboss Renal

Name one of the more common causes of stress incontinence in multiparous women.

Answer 24

Urethral hypermobility

Question 25

# Amboss Renal Name the main defective location in the kidney for each of the following: **Fan**coni syndrome **Bartter** **Gitel**man **Liddle**

Answer 25

_'**Fan**s **Bartter** and **Gitel** **Liddle** back'_ PCT Ascending LoH DCT CD

Question 26

# Amboss Renal Fanconi syndrome, a defect in the PCT, causes what main serum changes?

Answer 26

Type 2 tubular **acidosis** (normal anion gap) + **Hypokalemia** + **Hypocalcemia**

Question 27

# Amboss Renal Bartter syndrome, a defect in the ascending limb of the Loop of Henle, causes what main effects?

Answer 27

**Polyuria and muscle cramps; hypo-everything in early childhood** - hyponatremia - hypochloremia - hypokalemia - hypocalcemia - hypomagnesemia - metabolic alkalosis

Question 28

# Amboss Renal Gitelman syndrome is caused by a defect in the ______ \_\_\_\_\_\_\_\_\_\_ in the distal convoluted tubules.

Answer 28

Gitelman syndrome is caused by a defect in the **_Na_****⁺-_Cl_^-** **_cotransporters_** in the distal convoluted tubules.

Question 29

# Amboss Renal Gitelman syndrome, a defect in the descending convoluted tubule, causes what main effects?

Answer 29

**Fatigue, muscle cramps, polyuria, chondrocalcinosis in late-childhood** - hyponatremia - hypomagnesemia - hypokalemia - hypocalcemia - hypocalci*uria* - metabolic alkalosis

Question 30

# Amboss Renal Liddle syndrome is caused by a defect in the ______ in the collecting duct.

Answer 30

Liddle syndrome is caused by a defect in the **_ENaCs_** in the collecting duct.

Question 31

# Amboss Renal Liddle syndrome, a defect in the collecting duct ENaCs, causes what main effects?

Answer 31

**Hypokalemia, metabolic alkalosis, and hypertension in childhood** (all explained by a compensatory increase in sodium and water reuptake)

Question 32

# Amboss Renal Name the effect of DKA on each of the following in a patient's _urine_: **pH** **HCO₃^-** **NH₄⁺** **K⁺**

Answer 32

**Low** (ketones) **Low** (HCO₃^- reabsorbed) **High** (NH₄⁺​ excreted) **High** (lost in urine due to osmotic diuresis)

Question 33

# Amboss Renal A patient with some history of infection(s) presents with RBC casts in their urine. What is the first pathology on your differential to be considered?

Answer 33

IgA nephropathy | (Berger's disease)

Question 34

# Amboss Renal What type of urinary cast is seen in patients with minimal change disease?

Answer 34

Fatty casts

Question 35

# Amboss Renal RBC casts are associated with what three disease categories?

Answer 35

Nephritic syndromes; glomerular ischemia; malignant hypertension

Question 36

# Amboss Renal Identify the shape of each of the following crystal types on urinalysis: ## Footnote **Calcium phosphate** **Struvite** **Uric acid** **Cystine**

Answer 36

Wedge Coffin-lid Rhomboid or needle Hexagonal

Question 37

# Amboss Renal **True/False**. Urine alkalinization is an acceptable prophylaxis for urate nephropathy.

Answer 37

True.

Question 38

# Amboss Renal In addition to adequate hydration, which of the following is(are) most useful in preventing calcium nephrolithiasis? A. **High-oxalate diet** B. **Vitamin C supplementation** C. **Low-protein diet** D. **Low-calcium diet** E. **High-sodium diet**

Answer 38

C. **Low-protein diet** (The rest are risk factors: A., B., and D. all increases urinary oxalate levels; E. dehydrates the patient.)

Question 39

# Amboss Renal Which nerves innervate the detrusor muscle?

Answer 39

The **pelvic** **splanchnic** nerves | (damage may lead to atonic bladder)

Question 40

# Amboss Renal How can one prevent formation of _all_ forms of nephrolithiasis?

Answer 40

Adequate hydration

Question 41

# Amboss Renal **True/False**. Caffeine, coffee, and tea are all useful in decreasing the recurrence rate of nephrolithiasis.

Answer 41

**True**. ## Footnote *(Caffeine increases urinary flow; coffee and tea have antioxidant properties.)*

Question 42

# Amboss Renal **True/False**. Urinary acidification is useful in the prevention of all types of nephrolithiasis.

Answer 42

**False**. It is useful in preventing struvite and calcium phosphate stones _but not calcium oxalate_.

Question 43

# Amboss Renal What are the two locations in which abdominal bruits from renal artery stenosis can be auscultated?

Answer 43

The epigastrium (2-3 cm lateral); over the costovertebral angles

Question 44

# Amboss Renal **True/False**. Nephrolithiasis typically results in a normal finding in all of the following: **Serum Ca²⁺** **Serum uric acid** **Urine Ca²⁺** **Urine pH** **Urine cystine**

Answer 44

**False**. ## Footnote ***Urine calcium** will be increased and **urine pH** decreased.*

Question 45

# Amboss Renal What are the effects of amphotericin B as a result of the nephrotoxicity it sometimes has?

Answer 45

Type 1 renal acidosis; hypercloremic, hypokalemic, normal anion-gap metabolic acidosis

Question 46

# Amboss Renal Which naturally occurring substance combines with calcium in the urinary tract to prevent calcium stone formation?

Answer 46

Citrate

Question 47

# Amboss Renal **True/False**. Vitamin C is excreted in the urine as citrate, which decreases risk of calcium stone formation.

Answer 47

**False**. Vitamin C is excreted in the urine as ***oxalate***, which ***in***creases risk of calcium stone formation.

Question 48

# Amboss Renal What substance commonly found in high concentrations in energy drinks can increase risk of calcium nephrolithiasis?

Answer 48

Oxalate

Question 49

# Amboss Renal Cystinuria is characterized by decreased reabsorption of cystine, orthinine, lysine, and arginine in what location(s)?

Answer 49

The kidneys; the small intestine

Question 50

# Amboss Renal Patients with cystinuria and cystine nephrolithiasis have a positive urinary sodium ________________ test.

Answer 50

Patients with cystinuria and cystine nephrolithiasis have a positive urinary sodium **_cyanide nitroprusside_** test.

Question 51

# Amboss Renal In treating a spastic neurogenic bladder, one should administer a muscarinic \_\_\_\_gonist.

Answer 51

In treating a spastic neurogenic bladder, one should administer a muscarinic **_a_**gonist.

Question 52

# Amboss Renal What medication type increases urinary glucose excretion?

Answer 52

SGLT-2 inhibitors (-flozins really get the glucose flowin')

Question 53

# Amboss Renal What effect will dehydration have on the following: ## Footnote **Glomerular filtration rate** **Renal plasma flow** **Filtration fraction**

Answer 53

**Decreased** (\< RPF) **Decreased** (large decrease) **Increased** (FF = GFR/RPF) *(Basically, RPF decreases due to decreased blood volume; GFR decreases due to RAAS efferent arteriole constriction. Since GFR decreases less than RPF, FF actually increases.)*

Question 54

# Amboss Renal Name a normal urine osmolality (in mOsms) in each of the following locations: PCT Descending LoH Ascending LoH DCT (**100**) CD (**600**)

Answer 54

**300** **1200** **200** 100 600

Question 55

# Amboss Renal Name a normal urine osmolality (in mOsms) in each of the following locations: PCT (**300**) Descending LoH (**1200**) Ascending LoH DCT CD

Answer 55

300 1200 **200** **100** **600**

Question 56

# Amboss Renal **True/False**, PAH clearance decreases as plasma [PAH] increases.

Answer 56

Plasma [PAH] can saturate the organic acid transporters, inhibiting clearance of PAH from the remaining RPF

Question 57

# Amboss Renal Renal cell carcinomas typically arise from which portion of the nephron?

Answer 57

The PCT

Question 58

# Amboss Renal Why are the cells in renal cell carcinomas typically clear on microscopy and yellow on gross appearance?

Answer 58

High **lipid** and **glycogen** content

Question 59

# Amboss Renal Describe the effect of a renal NaCl transporter blocker in the DCT on serum levels of the following: ## Footnote **pH** **Potassium** **Calcium** **Sodium**

Answer 59

**Increased** (increased H⁺ exchange for Na⁺) **Decreased** (increased K⁺ exchange for Na⁺) **Increased** (unknown mechanism) **Decreased** (NaCl reuptake blockage)

Question 60

# Amboss Renal Desmopressin increases collecting duct permeability to what two substances via the V2 receptors?

Answer 60

**Water** (aquaporin₂) **Urea** (UT-A1​)

Question 61

# Amboss Renal Presence of WBC casts on urinalysis indicates inflammation of the renal \_\_\_\_\_\_\_\_\_\_\_.

Answer 61

Presence of WBC casts on urinalysis indicates inflammation of the renal **_interstitium_**.

Question 62

# Amboss Renal Long-term use of drugs like aspirin, tylenol, opioids, etc. coupled with hematuria is indicative of what?

Answer 62

Renal papillary necrosis

Question 63

# Amboss Renal Which segments of the nephron are most affected by ischemia?

Answer 63

The **straight PCT** + the **distal straight tubule** (aka the thick ascending limb)

Question 64

# Amboss Renal A neonate with Potter sequence shows evidence of periportal fibrosis and portal hypertension. Identify which of the following is the most likely precipitating cause of the presentation: **A. Bilateral renal hypoplasia** **B. Mutation of the short arm of chromosome 16** **C. Vesicoureteral reflux** **D. Nondisjunction of chromosome 18** **E. Nondisjunction of chromosome 13** **F. Cystic dilation of the collecting ducts**

Answer 64

**F. Cystic dilation of the collecting ducts** (ARPKD - mutation of the fibrocystin gene on the short arm of chromosome 6)

Question 65

# Amboss Renal What is the mechanism of atrial natriuretic peptide?

Answer 65

Afferent arteriole dilation Efferent arteriole constriction Decreased sodium reabsorption

Question 66

# Amboss Renal The level of ANP is proportional to ________ stretch. The level of BNP is proportional to ________ volume and pressure overload.

Answer 66

The level of ANP is proportional to **_atrial_** stretch. The level of BNP is proportional to **_ventricular_** volume and pressure overload.

Question 67

# Amboss Renal **True/False**. Post-renal acute kidney injury and hydronephrosis causes renal damage that is typically irreversible.

Answer 67

**False**. Post-renal acute kidney injury and hydronephrosis causes renal damage is typically ***reversible with medical intervention***.

Question 68

# Amboss Renal Identify the congenital renal syndromes associated with Wilms tumor that are caused by each of the following: ## Footnote **WT1 deletion** **WT1 mutation** **WT2 mutation**

Answer 68

WAGR Denys-Drash Beckwith-Wiedemann

Question 69

# Amboss Renal Muscarinic agonists ___________ bladder contraction. Muscarinic antagonists ___________ bladder contraction.

Answer 69

Muscarinic agonists **_increase_** bladder contraction. Muscarinic antagonists **_decrease_** bladder contraction.

Question 70

# Amboss Renal A patient with oliguria due to short-term hypovolemia (precipitating prerenal ATN in the long-term) is most likely to have what urinalysis results as far as sodium and casts are concerned?

Answer 70

**Low sodium** + **hyaline casts**

Question 71

# Amboss Renal A heterogenous mass arising from the **renal pelvis** is most likely (90%) to be what kind of tumor?

Answer 71

Urothelial carcinoma

Question 72

# Amboss Renal **True/False**. Creatinine is freely filtered at the glomerulus, with no passive reabsorbtion or active secretion.

Answer 72

**False**. Creatinine is freely filtered at the glomerulus, ***minimally passively reabsorbed, and small amounts are*** actively secreted.

Question 73

# Amboss Renal Which overestimates renal clearance, creatinine or inulin?

Answer 73

**Creatinine** | (10 - 20% actively secreted)

Question 74

# Amboss Renal **True/False**. Inulin is freely filtered at the glomerulus, with no passive reabsorbtion or active secretion.

Answer 74

True.

Question 75

# Amboss Renal What are the renal effects seen with tacrolimus-induced injury?

Answer 75

**Tubular vacuolization** + possible glomerular scarring and focal segmental glomerulosclerosis

Question 76

# Amboss Renal What are the renal effects seen with sirolimus-induced injury?

Answer 76

**None**. There are no renal effects of sirolimus use.

Question 77

# Amboss Renal The levator ani are innervated by which nerve roots?

Answer 77

S3 - S4

Question 78

# Amboss Renal Which type of diuretic is useful in preventing calcium stones?

Answer 78

**Thiazides** | (calcium-sparing)

Question 79

# Amboss Renal **True/False**. Inermittent catheterization can be useful as treatment for patients with neurogenic bladder.

Answer 79

True.

Question 80

# Amboss Renal Describe the difference in etiology between the two forms of renal arteriolosclerosis shown in the image.

Answer 80

The left image shows **hyperplastic** arteriolosclerosis due to **acute-onset hypertensive emergency**; the right image shows **hyaline** arteriolosclerosis due to **chronic hyperglycemia**

Question 81

# Amboss Renal In a pregnant patient with gonorrhea, what is the treatment plan?

Answer 81

IM **ceftriaxone** + oral **azithromycin** *(The pregnancy does not alter treatment.)*

Question 82

# Amboss Renal What drug is a second-line agent used to inhibit uric acid reabsorption in the PCT?

Answer 82

Probenecid

Question 83

# Amboss Renal Cigarette smoking and chronic ergotamine use are both risk factors for what?

Answer 83

**Retroperitoneal fibrosis** *(abdominal irradiation, retroperitoneal surgeries, and IgG4-related systemic diseases are also risk factors)*

Question 84

# Amboss Renal Name some of the potential treatments for nephrogenic diabetes insipidus.

Answer 84

**Indomethacin** **Thiazides** **Amiloride** (if lithium-induced)

Question 85

# Amboss Renal Bilateral, irregular areas of dilation and constriction in the renal arteries is characteristic of what form of autoimmune condition causing transmural inflammation and fibrinoid necrosis of the arteries?

Answer 85

**Polyarteritis nodosa**

Question 86

List the main features of type 1 renal tubular acidosis. ## Footnote *(Main issue, pH changes, potassium changes, other issues, etc.)*

Answer 86

**Distal RTA** Impaired H⁺ secretion Elevated urine pH Hypokalemia Nephrolithiasis

Question 87

List the main features of type 2 renal tubular acidosis. ## Footnote *(Main issue, pH changes, potassium changes, other issues, etc.)*

Answer 87

**Proximal RTA** Impaired HCO₃^- reabsorption Initially high but decreasing urine pH Hypokalemia

Question 88

List the main features of type 4 renal tubular acidosis. ## Footnote *(Main issue, pH changes, potassium changes, other issues, etc.)*

Answer 88

**Hyperkalemic RTA** Impaired aldosterone action *(either due to resistance or decreased secretion)* Low urine pH Hyperkalemia