UWorld Targeted Review: Pulm/Renal

Question 1

what type of lung pathology results in increased expiratory flow rates, and why does this occur?

Answer 1

interstitial lung disease = decreased lung volumes + increased lung elastic recoil caused by fibrotic tissue

increased elastic recoil —> increased radial traction (outward pulling) on airways —> increased expiratory flow rates (when corrected for low lung volume)

Question 2

what do pulmonary function tests show in interstitial lung disease? (4)

Answer 2

interstitial lung disease = restrictive

1. supernormal expiratory flow rates due to radial traction (outward pulling) by fibrotic tissue
2. reduced total lung capacity, vital capacity, inspiratory capacity, functional residual capacity, residual volume
3. normal or elevated FEV1/FVC ratio (FEV1 decreases less than FVC)
4. reduced DLCO

Question 3

what type of pneumoconiosis is histologically characterized by birefringent particles surrounded by dense collagen fibers?

Answer 3

silicosis - causes dyspnea on exertion and production cough 10-20 years after exposure

CXR shows rounded nodules in upper lobes and eggshell calcification of rim hilar nodes

Question 4

what forms concentrically laminated structures and appears pink with PAS staining in the lungs?

Answer 4

surfactant - lipoproteinaceous material, forms lamellar bodies that can be seen on EM

surfactant is secreted by Type 2 pneumocytes and cleared by alveolar macrophages

Question 5

function of alveolar macrophage vs club cell vs goblet cell in the lungs

Answer 5

alveolar macrophage: clearance of debris (surfactant, pathogens, inhaled particulates)

club cell: protection and repair of distal airway (tobacco smoke detoxification)

goblet cell: secretion of mucins (goblet metaplasia occurs in COPD/asthma)

Question 6

what is the V/Q ratio in the apex vs base of lungs

Answer 6

ventilation (V) is lowest in apex, highest in base - alveoli are stretched by gravity at the top and less compliant, so air more easily enters alveoli at the base

perfusion (Q) is also lowest in apex, highest in base - gravity pulls blood down, and the effect of gravity is greater on perfusion than ventilation

taken together… V/Q ratio is lowest at the base, highest at the apex (think higher at the highest point of the lungs)

Question 7

how do obstructive vs restrictive lung diseases alter the respiratory flow-volume curve?

Answer 7

obstructive: LEFTWARD shift due to increased total lung capacity and residual volume (lung volume decreases to the right!) + scooped out pattern on top of loop due to reduced expiratory flow rates

restrictive: RIGHTWARD shift due to decreased TLC/RV + smaller loop due to decreased volumes

Question 8

how does FEV1/FVC ratio differ with obstructive vs restrictive lung disease?

Answer 8

obstructive = DECREASED FEV1/FVC ratio (FEV1 more affected) despite increase in lung volumes

restrictive = normal or increased FEV1/FVC ratio (FVC more affected) despite decrease in lung volumes

Question 9

what is the cause of pulmonary alveolar proteinosis?

Answer 9

impaired clearance of surfactant by alveolar macrophages —> accumulation of proteinaceous material (surfactant) within alveoli

Question 10

what are the important risk factors for bladder cancer? (2)

Answer 10

1. tobacco smoke
2. occupational - rubber, plastics, dyes, textiles, leather

Question 11

with which nephropathy is penicillamine associated?

Answer 11

penicillamine: copper-chelating agent used to treat Wilson disease

associated with membranous nephropathy (nephrotic)

Question 12

MOA sevelamer

Answer 12

sevelamer: non-absorbable anion-exchange resin that binds and inhibits phosphate to reduce absorption (oral phosphate binder)

used to treat hyperphosphatemia in patients with CKD

Question 13

which of the following findings suggests prerenal ARF?
a. serum BUN/Cr ratio <15
b. urine fractional excretion of sodium >2%
c. urine osmolarity <350 mOsm/kg
d. urine sodium <20 mEq/L

Answer 13

d. urine sodium <20 mEq/L

would also see low fractional excretion of Na+, high urine osmolarity, and BUN/Cr ratio >20 - these all indicate intact renal tubular function

[all other options reflect intrinsic ARF - due to diminished reabsorption ability]

Question 14

Heterogenous mixture of chronic inflammation and patchy interstitial fibrosis in the lung periphery =

Answer 14

idiopathic pulmonary fibrosis - will also see focal fibroblast proliferation and formation of fibrotic cystic spaces in a honey comb pattern

Question 15

Hyaline membranes are composed of…

Answer 15

Plasma proteins and necrotic epithelial cells

Question 16

as fetal lungs mature, the ratio of ___ to _____ increases

Answer 16

lecithin (aka phosphatidylcholine) to sphingomyelin ratio increases

lung maturity = L/S > 2

[the presence of phosphatidylglycerol (lipid component of surfactant) also increases, but this is a separate thing]

Question 17

neutrophil elastase is inhibited by _____, and macrophages elastase is inhibited by _____

Answer 17

neutrophil elastase is inhibited by alpha-1 antitrypsin, and macrophages elastase is inhibited by inhibitors of metalloproteinases

neutrophils and macrophages can degrade each other’s inhibitors to augment destructive capacity

Question 18

biopsy of hypersensitivity urticaria (hives) would show:
a. acantholysis.
b. Acanthosis.
c. Dermal edema.
d. Dyskeratosis
e. Epidermal spongiosis

Answer 18

c. Dermal edema - due to increased vascular permeability

a. acantholysis = loss of cohesion between keratinocytes in the epidermis (pemphigus)
b. Acanthosis = diffuse increase in the thickness of the stratum spinosum (psoriasis, acanthosis nigricans)
d. Dyskeratosis = premature keratinization (SCC)
e. Epidermal spongiosis = intercellular epidermal edema (eczema)

Question 19

Hemosiderin-laden macrophages with congested air spaces are consistent with =

Answer 19

Cardiogenic pulmonary edema

Question 20

which of these features can be found most distally in the respiratory tract?
a. Cartilage
b. Cilia
c. Goblet cells.
d. Mucous glands
e. serous glands.

Answer 20

b. Cilia - present through proximal portions of respiratory bronchioles, not present in alveolar ducts

Goblet cells (mucous) are present until terminal bronchioles, which contain club cells (secretory protein)

submucosal mucous and serous glands are present until bronchioles

Question 21

how is the Reid index calculated?

Answer 21

Ratio of the thickness of submucosal glands to the thickness of the bronchial wall between the epithelial basement membrane and the bronchial cartilage (deep and superficial to glands)

Question 22

what is the blood supply to the proximal vs distal ureter?

Answer 22

proximal - renal artery (this is the same for both sides!!)

distal - superior vesical artery

in between - variable, anastomotic

Question 23

the female ureters pass posterior to the ______ vessels within the retroperitoneum and cross anterior to the _____ arteries to reach the true pelvis; within the true pelvis, the ureters lie anterior to the ________ artery and posterior to/ under the _______ artery

Answer 23

the female ureters pass posterior to the ovarian vessels (arising from aorta/IVC) within the retroperitoneum and cross anterior to the common/external iliac arteries to reach the true pelvis;

within the true pelvis, the ureters lie anterior to the internal iliac artery and posterior to/under the uterine artery (water under the bridge) (arising from the internal iliac)

Question 24

rupture of which portion of the bladder can cause intraperitoneal bleeding?

Answer 24

bladder dome - the only part that sticks up into the peritoneum (the rest is extra-peritoneal)

Question 25

what is the cause of each type of urinary incontinence?
a. stress
b. urge
c. overflow

Answer 25

a. stress (leakage with coughing, lifting) - low urethral sphincter tone/ dysfunction (obstetric trauma damages urethral sphincter or pudendal nerve)

b. urge (sudden, overwhelming urge) - detrusor overactivity

c. overflow (incomplete emptying, dribbling) - impaired detrusor contractility or bladder outlet obstruction

Question 26

fetal hydronephrosis is most commonly due to unilateral and transient narrowing in the ________ junction

Answer 26

ureteropelvic junction

Question 27

the renal parenchyma are derived (most directly) from…
a. mesonephric duct
b. mesonephros
c. metanephros
d. pronephros
e. urogenital ridge

Answer 27

c. metanephros

pronephros/mesonephros degenerates

mesonphric duct persists as ureteric bud

urogenital ridge gives rise to nephric system, gonads, repro tract, and adrenal cortex

Question 28

what are the paraneoplastic syndromes of renal cell carcinoma?

Answer 28

EPO production (elevated hemoglobin) and PTHrP (hypercalcemia)

Question 29

immunofluorescence microscopy shows “full house” with three immunoglobins classes (IgG, IgM, IgA) and two complement components (C3, C1Q) =

Answer 29

Lucas nephritis from SLE (glomerulonephritis)

EM shows abundant subendothelial electron dense deposits

Question 30

What muscle is the target of Kegel exercises?

Answer 30

levator ani muscle complex (iliococcygeus, pubococcygeus, puborectalis), aka the “pelvic floor”

used in patients with stress incontinence (due to internal urethral sphincter dysfunction)

Question 31

NSAID-induced kidney injury is due to impaired…

compare this to ACEi-induced kidney injury

Answer 31

NSAIDs —> impaired afferent arteriole vasodilation

ACEi —> impaired efferent arteriole vasoconstriction

both cause prerenal azotemia, harmful in patients with volume depletion (CHF) who rely on GFR

Question 32

elevated renin activity + elevated aldosterone levels + increased potassium excretion = [tumor]

Answer 32

Juxtaglomerular cell tumor: secrete renin, which activates aldosterone

non-neoplastic causes could be malignant HTN or diuretic use

Question 33

renal cell carcinoma often invades the renal vein which can lead to obstruction of…

Answer 33

Inferior vena cava – produces symmetric bilateral lower extremity edema and tortuous abdominal veins