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STEP1 Review > NBME Exam Review > Flashcards

NBME Exam Review Flashcards

1
Q

what is the effect of opioids binding the following opioid receptor types:
a. mu
b. delta
c. kappa
d. sigma

A

mu: analgesia, reward, adverse CNS/PNS effects (respiratory depression)

delta: analgesia, reward, neuronal adaptations leading to addiction

kappa: analgesia, oppose reward signaling (–> dysphoria under stressful conditions)

sigma: regulate higher-order functions such as memory and drug dependence

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2
Q

what is the role of the following cell types?
a. luteal cell
b. granulosa cell
c. theca externa
d. theca interna

A

a. luteal cell: present in corpus luteum, derived from granulosa cells of pre-ovulatory follicle; secrete estrogen and progesterone

b. granulosa cell: convert androgens (received from theca interna) into estradiol via aromatase

c. theca externa: make up loose connective tissue (fibroblasts, macrophages, smooth muscle)

d. theca interna: generate androstenedione from cholesterol

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3
Q

what are the stages of the cell cycle?

A

G0: cell cycle arrest
G1: enzymes necessary for DNA replication are synthesized (everything is duplicated except chromosomes)
S: DNA replication
G2: integrity of duplicated genome is checked, growth phase
M: mitosis + cell division

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4
Q

most common cause of mouth sores, exacerbated by spicy/acidic foods, dental work, or emotional stress

A

aphthous ulcers: painful, round, shallow oral ulcers; common in adolescence/young adulthood

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5
Q

of what is geographic tongue a feature, and how does it appear?

A

geographic tongue: feature of psoriasis in children, looks like maze of white linear patches

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6
Q

how do Koplik spots appear?

A

bright red macules with bluish-white center on buccal mucosa

due to measles infection, will be accompanied by fever+cough+coryza+conjunctivitis and maculopapular rash starting on head/neck –> trunk (excluding palm/soles)

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7
Q

with what is leukoplakia associated?

A

leukoplakia: white plaques in mouth which cannot be scaped off

due to underlying EBV infection, common in patients with HIV or malignancy

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8
Q

oral white patches with stellate appearance =

A

oral lichen planus

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9
Q

cross-section of liver showing innumerable lesions is most likely due to metastasis from where?

A

colorectal carcinoma (CRC)

remember - primary cancer produces single lesions, while metastasis produces many

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10
Q

why should ACE inhibitors be used with caution in patients with renal artery stenosis?

A

cause dilation of efferent arterioles –> transient decrease in GFR

in patients with renal artery stenosis, nephron is dependent on efferent vasoconstriction (via angiotensin II) to maintain adequate filtration pressure

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11
Q

with which classes of antibiotics (2) are aminoglycosides synergistic?

A

aminoglycosides (gentamicin, neomycin, amikacin, tobramycin, streptomycin) inhibit 30s bacterial ribosome

synergistic with penicillins, which inhibit peptidoglycan cross-linking of bacterial wall, and monobactams (aztreonam), which also target peptidoglycan cross-linking function (but require O2)

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12
Q

which muscle supinates the forearm?

A

biceps brachii: supinates the forearm + flexes the elbow

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13
Q

what causes neonatal hypoglycemia in children born from diabetic mothers?

A

decreased gluconeogenesis - human placental lactogen produced by the placenta increases maternal insulin resistance –> increased glucose in maternal circulation

fetal hyperglycemia causes fetus to produce excess insulin and decrease gluconeogenesis

at birth, fetus continues to synthesize insulin but is no longer exposed to maternal blood glucose levels –> hypoglycemia

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14
Q

melanocortin 2 receptor =

A

ACTH receptor

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15
Q

[motor/parasympathetic] fibers from the ____ nerve innervation all muscles of the pharynx except the ______ muscle

A

motor fibers from the vagus nerve innervation all muscles of the pharynx except the stylopharyngeus muscle (innervated by glossopharyngeal nerve)

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16
Q

how does actinic keratosis vs lentigo maligna appear?

A

actinic keratosis (pre-malignant to squamous cell carcinoma): light pink, gritty texture, in areas of sun exposure

lentigo maligna (subtype of melanoma): slow-growing, brown-black, scaly, irregular borders, in areas of sun exposure of elderly patients (appears like melanoma.. because it is !)

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17
Q

tumor biopsy shows malignant, small, blue neoplasm expressing cytokeratin, chromogranin, and synaptophysin - what kind of tumor is this?

A

pulmonary small cell carcinoma

don’t be confused if this biopsy is found outside the lung - could be metastasis! (esp. brain)

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18
Q

which part of the intestines is most often affected by diverticulosis?

A

sigmoid colon - has small diameter, predisposing to greater intraluminal pressure

diverticulosis = mucosa + submucosa herniates through muscular layer

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19
Q

pediatric patient w/ increased urinary excretion of alanine, isoleucine, leucine, phenylalanine, tryptophan, and valine

what is the dx, and for which vitamin deficiency are they at risk for?

A

dx = Hartnup disease: AR defect in amino acid transporter (kidney and intestines) –> deficiency of neutral amino acids

at risk for niacin (B3) deficiency (niacin is derived from tryptophan) –> dementia, dermatitis, diarrhea

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20
Q

screening tests require high [sensitivity/specificity], while confirmatory tests require high [sensitivity/specificity]

A

screening tests require high sensitivity (able to detect disease)

confirmatory tests require high specificity (able to rule out disease)

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21
Q

fixed split S2 =

A

atrial. septal. freaking. defect.

due to increased SV of RV –> delayed closure of pulmonary valve

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22
Q

somatic symptom disorder vs conversion disorder vs factitious disorder vs malingering and pleasedontmakemewasteanymorecardsdonthis

A

somatic symptom disorder: preoccupation with 1+ somatic symptoms (may or may not originate from underlying disease), patient spends a lottt of time trying to “cure” these

conversion disorder: aka functional neurological disorder, these are gonna be sensory or motor “dysfunctions” (not explained by clinical findings)

factitious disorder: goal is primary gain (to be cared for)

malingering: goal is secondary gain (disability payments)

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23
Q

Infant presenting with lethargy, vomiting, poor feeding, hepatomegaly, and seizures. Labs show increased levels of argininosuccinate, citrulline, and ammonia. What enzyme is defective?

A

dx = argininosuccinic aciduria: mutation in argininosuccinate lyase (ASL), which converts argininosuccinate to arginine

these are intermediates in the urea cycle - therefore, results in defective conversion of ammonia to urea

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24
Q

where can the great saphenous vein be palpated?

A

great saphenous vein - longest vein in body, runs along medial aspect of leg, can be palpated along the anterior aspect of the medial malleolus of the ankle

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25
Q

18yo F being evaluated for amenorrhea. She has never had a menstrual period. She is 6ft and has normal breast and external genitalia development. There is no axillary or pubic hair. What is the most likely karyotype?

A

dx = androgen insensitivity syndrome: 46,XY (M) genotype with F phenotype

testes are present and produce testosterone, absent internal F genitalia, rudimentary vagina

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26
Q

which vitamin is used in the treatment of psoriasis?

A

Vitamin D - plays a role in immune modulation via binding nuclear TF

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27
Q

MOA of sildenafil

A

inhibits cGMP-specific phosphodiesterase-5 (PDE-5) –> increase in NO (and therefore vascular dilation) in the corpus cavernosa (pair of richly vascularized erectile bodies in shaft)

used to treat ED

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28
Q

urea vs uric acid

A

urea: metabolic product of cystine, soluble in water, reabsorbed in nephron to create hyperosmolar gradient surrounding loop of Henle - does NOT cause AKI or hyperuricemia

uric acid: NOT water soluble and may crystallize, causes many problems

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29
Q

what is the FEV1/FVC ratio in obstructive vs restrictive lung disease?

A

obstructive = FEV1/FVC < 0.7 (DECREASED)

restrictive = FEV1/FVC > 0.8 (INCREASED)

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30
Q

child presenting with bilateral aching in the temples, cognitive impairment, mood swings and irritability, hallucinations, and broad-based/ataxic gait most likely has had chronic exposure to what type of toxin?

A

inhalants (ex, glue) - distinguished from other toxic manifestations by headache and cerebellar dysfunction

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31
Q

decreased urinary output following episode of hypotension = what kind of kidney injury? Which area of the kidney is most heavily affected by the prolonged hypotension?

A

acute tubular necrosis (ATN) - most heavily affects PCT, which is why sloughing of tubular cells leads to muddy brown casts in urine

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32
Q

what are LINE sequences

A

LINE = long interspersed nuclear element

method of bacterial genetic variation through transposable elements (segment of DNA moves from chromosome to plasmid)

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33
Q

Child w/ migraine-like headaches, vomiting, and multiple L-sided focal seizures. She has had hearing loss since 11yo. Her mother and maternal grandmother have high-tone deafness. PE shows weakness in R upper and lower extremities. Serum and CSF lactic acid are increased. Dx?

A

mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) - mutation in mitochondrial tRNA

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34
Q

female with taut, smooth facial skin without wrinkles should raise suspicion of…

A

systemic sclerosis (scleroderma): autoimmune collagen deposition and progressive fibrosis, more commonly affects females

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35
Q

what is the rate-limiting step of peripheral nerve regeneration?

A

slow anterograde axonal transport of newly synthesized cytoskeleton and cytoplasmic proteins to axon terminal

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36
Q

the spinothalamic tract is organized somatotopically such in the spinal cord such that lateral region controls ______, while the anterior region controls ______

A

lateral = pain/temp
anterior = crude touch/pressure

37
Q

most common bacteria (3) to cause pneumonia in patients with chronic granulomatous disease (NADPH oxidase deficiency)? most common fungal cause?

A
  1. Staphylococcus species
  2. Burkholderia cepacia
  3. Nocardia species

also at risk for fungal infections by Aspergillus

38
Q

which cancers (2) most commonly metastasize to vertebrae?

A

breast and prostate

[just think of the vertebral column connecting these two organs]

39
Q

which topical medication used for primary open angle glaucoma may cause SOB and decreased FEV1?

A

beta blockers (timolol) - beta inhibition in the ciliary body reduces formation of aqueous humor

relatively contraindicated in patients with asthma

40
Q

how can chronic autoimmune (Hashimoto) thyroiditis be differentiated from granulomatous thyroiditis on PE?

A

Hashimoto’s: thyroid is firm, nodular, diffusely enlarged, symptoms of hypothyroidism

granulomatous (de Quervain): follows viral illness, symptoms of hyperthyroidism, thyroid is painful and tender

41
Q

deficiency of which of the following can lead to symptoms of peripheral neuropathy and retinitis?
a. Apo A-I
b. Apo A-II
c. Apo B
d. Apo C
e. Apo E

A

c. Apo B: essential component of LDL, IDL, and VLDL - required for normal absorption/trafficking of lipids to/from intestines and liver

mutations in MTP gene lead to absent/reduced Apo B –> chronic malabsorptive diarrhea + deficiencies of DAKE vitamins –> neurological manifestations

42
Q

what is the consequence of lack of scrotal attachment to the gubernaculum?

A

undescended testes due to inability of gubernaculum to guide the testis through the inguinal canal to the scrotum

43
Q

what is the infectious cause of epididymitis with thick, green urethral discharge?

A

Neisseria gonorrhoeae

epididymitis presents with fever, purulent urethral discharge, and pain localized to 1 testis which may be alleviated by elevation of that hemiscrotum

[Chlamydia can also cause epididymitis, but would not cause green discharge]

44
Q

transfer of electrons from NADH to coenzyme Q = which complex of ETC?

A

complex I - transfer generates a proton gradient

45
Q

transfer of electrons from ubiquinol to cytochrome c = which complex of ETC?

A

complex III - transfer generates a proton gradient

46
Q

which organelles are the site of combination of antigen and MHC I vs MHC II synthesis, respectively?

A

endoplasmic reticulum = site of combining target peptides with MHC I

endosomes = site of combining antigens and MHC II
[note MHC II are synthesized in ER, but trafficked to late endosomes]

47
Q

which of the following is consistent with pneumonia?
a. muffled whispered sounds over R lower lung field
b. increased tactile fremitus over R lower lung field
c. vesicular breath sounds over R lower lung field

A

b. increased tactile fremitus over R lower lung field - relies on increased sound wave transmission and vibrations through consolidated lung tissue (as compared with normal, aerated lung tissue)

muffled whispers are normal - clear and easily audible indicates pneumonia

vesicular breath sounds are normal

48
Q

woman with unexplained thrombocytopenia a month after a viral respiratory infection =

A

immune thrombocytopenic purpura (ITP): anti-GpIIb/IIIa antibodies bind platelets –> peripheral destruction of platelets

diagnosis of exclusion, often follows viral illness

49
Q

function of L-type Ca2+ channel vs Na+/Ca2+ exchanger vs ryanodine receptor

A

L-type (dihydropyridine channel): voltage-gated, opens during phase 2, coupled with ryanodine receptor

ryanodine receptor: releases Ca2+ from SR to cytoplasm

Na+/Ca2+: brings Na+ into cytoplasm and Ca2+ out of cytoplasm to stop contraction

50
Q

what cell type is predominant in induration following PPD skin test?

A

MACROPHAGES - CD8 T cells are there too but are NOT predominant

macrophages are also predominant in lungs of patients with TB

51
Q

what is the mechanism by which oxidizing free radicals generated by acetaminophen overdose damage hepatocytes?

A

acetaminophen overdose –> CYP-mediated reactions to NAPQI, which generates free radicals

free radicals damage hepatocytes through lipid peroxidation in cell membranes, oxidative damage to proteins, and strand breaks in DNA

52
Q

what are the paraneoplastic syndromes of small cell lung carcinoma? (3)

A
  1. ACTH - Cushing syndrome
  2. SIADH
  3. LEMS (Lambert-Eaton)
53
Q

decubitus ulcers =

A

pressure sores

54
Q

harsh, high-pitched holosystolic murmur that radiates over precordium and a palpable thrill at the L sternal border =

A

ventricular septal defect

[atrial septal defect = fixed split S2 + low grade ejection murmur]

55
Q

what are the symptoms of I-cell disease?

A

developmental delay/delayed growth, coarse facial features, generalized hypotonia, restricted skeletal development, hepatosplenomegaly, cardiac structural defects, corneal clouding, dwarfism

[AR inheritance, defect in mannose residue phosphorylation of lysosomal hydrolases]

56
Q

which of the following contributes to lateral rotation of the thigh?
a. gluteus minimus
b. piriformis
c. rectus femoris

A

b. piriformis

other lateral rotators include obturator internus and externus, gemelli, and quadratus femoris

[gluteus minimus - hip abduction and internal rotation]

57
Q

which cells secrete inhibin in males vs females, and what is its direct action?

A

F - granulosa cells
M - Sertoli cells

acts to inhibit FSH at the level of the pituitary

58
Q

what is the mechanism of hypercalcemia in multiple myeloma?

A

malignant plasma cell clones locally secrete IL-1, TNFa, and RANK-L to stimulate osteoclasts

59
Q

portal HTN can be transmitted through which of the following veins?
a. hepatic
b. short gastric
c. suprarenal

A

b. short gastric

other options drain into IVC (systemic, not portal)

60
Q

tumor biopsy stains positive for desmin - what type of tissue is it?

A

MUSCLE

desmin = intermediate filament

61
Q

MOA of each of the following?
a. flucytosine
b. amphotericin B/ nystatin
c. echinocandins
d. fluconazole

A

a. flucytosine - inhibition of DNA and RNA synthesis
b. amphotericin B/ nystatin - pore formation in fungal cell membrane
c. echinocandins - prevention of cross-linking of beta-glucans in cell wall
d. fluconazole - inhibits production of ergosterol via inhibiting cytochrome P450-dependent demethylation reactions

62
Q

what gene is mutated in AR vs AD polycystic kidney disease?

A

AR (juvenile) - fibrocystin

AD (adult) - polycystin (PKD1 or PKD2)

63
Q

the rate of shortening within a muscle is governed by:
a. rate of Na/K ATPase activity
b. amount of muscle phosphocreatine
c. rate of cross-bridge recycling
d. frequency of action potentials

A

c. rate of cross-bridge recycling

64
Q

What is the difference between embolism and thrombus?

A

An embolus is a particle or mass that flows through the bloodstream. A thrombus is a blood clot in a blood vessel. If a thrombus breaks off, it can become an embolus.

65
Q

what are the 3 points of narrowing along the course of the ureter?

A
  1. ureteropelvic junction of the renal pelvis and ureter
  2. ureterovesical junction as ureter enters posterior bladder
  3. pelvic inlet when ureter crosses the external iliac vessels
66
Q

what is derived from the following?
a. diencephalon
b. telencephalon
c. mesencephalon
d. metencephalon
e. prosencephalon

A

prosencephalon –> telencephalon (cerebral hemispheres, lateral ventricles) + diencephalon (thalamus, hypothalamus, third ventricle)

mesencephalon –> midbrain + cerebral aqueduct

metecephalon –> pons, cerebellum, fourth ventricle

67
Q

function of clathrin-coated pits vs COPII-coated pits

A

clathrin-coated: main structures on cell membrane involved in receptor-mediated endocytosis

COPII: involved in molecular transport of substances from ER to Golgi apparatus

68
Q

congenital diaphragmatic hernia is due to impaired development of the ______ membrane

A

pleuroperitoneal membrane

69
Q

relative risk (RR) is considered significant when the confidence interval (CI) [does/doesn’t] cross 1.0

A

RR is significant when CI DOES NOT cross/include 1.0

[CI including 1.0 = not statistically significant]

70
Q

case-control vs cohort vs case series

A

case-control: patients with/without DISEASE are matched, and exposure data is collected –> odds ratio (OR)

cohort: patients with/without EXPOSURE are matched, and outcome data is collected –> relative risk (RR)

case series: for rare diseases, follow progression of patient disease and treatment - useful for characterizing natural history of disease or response to treatment, do not imply cause/effect or test a hypothesis

71
Q

what is produced by acidophils vs basophils

A

The acidophils secrete GH (somatotropes) and prolactin (mammotropes).

Basophils secrete TSH (thyrotropes), LH (gonadotropes), FSH (gonadotropes), and ACTH (corticotropes)

72
Q

patient presenting with N/V, epigastric abdominal pain radiating to the back, and bruising of both flanks =

A

acute pancreatitis - often in patient with history of gallstones, alcoholism, trauma, hypertriglyceridemia, or hypercalcemia

Grey-Turner sign = bruising of flanks
Cullen sign = bruising around umbilicus

73
Q

patients with methylmalonic acidemia should avoid _____, and some patients may respond to supplementation of _____

A

patients with methylmalonic acidemia should avoid protein, and some patients may respond to supplementation of B12 (cobalamin)

methylmalonyl-CoA mutase catalyzes conversion of methylmalonyl-CoA to succinyl-CoA, which is important for metabolism of branched-chain AA (isoleucine, valine, threonine, methionine), and B12 is a cofactor

74
Q

which veins can provide an alternate route for blood from upper extremities and head/neck to return to IVC in the setting of superior vena cava syndrome?

A

intercostal and internal mammary veins

SVC syndrome presents with cough, swelling of face/neck, increased JVD, upper extremity swelling, distended chest vein collaterals, and conjunctival edema

75
Q

patient w/ PMH of cerebellar hemangioblastoma and retinal angiomas is most likely to develop what type of renal cancer?

A

renal adenocarcinoma (renal clear cell carcinoma) - comprised of tubular epithelial cells

dx = vHL syndrome

76
Q

how are levels of the following affected by B12 deficiency?
a. methionine
b. methylmalonate

A

a. methionine: DECREASED due to decreased conversion of homocysteine to methionine

b. methylmalonate: INCREASED due to decreased conversion of methylmalonyl-CoA to succinyl-CoA

77
Q

holoprosencephaly is a congenital malformation of:
a. diencephalon
b. mesencephalon
c. prosencephalon
d. rhombocephalon
e. telencephalon

A

c. prosencephalon - origin of cortical hemispheres, lateral ventricles, thalamus, hypothalamus

not telencephalon because it is named following differentiation from prosencephalon, not before

78
Q

hyperacute rejection is caused by…

A

preformed antibodies which activate compliment and cause thrombosis

79
Q

what type of brain bleed can result in sudden LOC w/ pinpoint pupils and decorticate posturing?

A

intraparenchymal - associated with uncontrolled HTN, often occur in putamen, thalamus, pons, cerebellum

decorticate posturing = above red nucleus

80
Q

the target of the influenza vaccine is…

A

hemagglutinin

[neuraminidase is target of oseltamivir]

81
Q

MOA albendazole

A

binds to tubulin and inhibits microtubule polymerization

82
Q

MOA fluconazole

A

inhibition of cytochrome P450-dependent demethylation system - inhibits formation of ergosterol (part of fungal cell membrane)

83
Q

MOA flucytosine

A

inhibition of DNA/RNA synthesis

84
Q

what is the consequence of perforation of an anterior vs a posterior duodenal ulcer?

A

anterior –> pneumoperitoneum
posterior –> hemorrhage of gastroduodenal artery

85
Q

which of the following describes the location of the AV node?
a. posteroinferior region above the opening of the coronary sinus
b. superoanterior region above the limbus of the fossa ovalis
c. superoposterior region posterior to the fossa ovalis

A

a. posteroinferior region above the opening of the coronary sinus

86
Q

what are the lab findings of euthyroid sick syndrome?

A

abnormalities in thyroid function testing that occur in setting of acute systemic illness (likely part of acute phase response)

decreased free T3, normal/low T4 and free T4, normal TSH

clinically euthyroid, do not have symptoms of hypothyroidism

87
Q

anti-mitochondrial antibodies =

A

primary biliary cholangitis: autoimmune disorder of intralobular bile ducts

presents in middle-age women w/ pruritis, fatigue, cholestasis, jaundice, hepatosplenomegaly, DAKE deficiency

88
Q

histology of Takayasu arteritis shows…

A

graulomatous inflammation

[large vessel vasculitis affecting young female patients, weak pulses caused by narrowing of aortic arch/proximal great vessels]

89
Q
A

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