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Flashcards in USMLE World 1 Deck (170)
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1
Q

relantionship between prevalence and PPV

A

Prevalence ∝ PPV/NPV

2
Q

top cancers by incidence

A
  1. breast/prostate; 2. lung; 3. colon
3
Q

top cancers by prevalence

A
  1. breast/prostate; 2. colon; 3. lung
4
Q

respiratory epithelium

A

cilia is present all throughout; serous, mucous glands, goblet cells and cartilage dissappear

5
Q

koilocytes

A

pyknotic superficial immature squamous cell with dense irregularly stainning cytoplasm and perinuclear clearing

6
Q

osteocytes

A

gap junctions

7
Q

elastase

A

protease secreted by alveolar macrophages

8
Q

dynein

A

ATPase associated with microtubule doublets; retrograde transport and ciliary flagellar movement

9
Q

type II pneumocytes

A

production of surfactant and regeneration of type I pneumocytes after injury

10
Q

Brunner glands

A

only in duodenum

11
Q

Peyer patches

A

mostly in ileum

12
Q

histology of large intestine

A

goblet cells but no pits or villi

13
Q

stratified epithelium of the respiratory tract

A

oropharynx, laryngopharynx, anterior epiglotis, true vocal cords

14
Q

strep bovis endocarditis

A

associated with colon cancer 25% of cases

15
Q

dextran adherence

A

viridans strep adheres to deposits of fibrin in damaged valves

16
Q

congenital rubella

A

sensorineural deafness, cataracts and PDA

17
Q

fulminant hepatitis

A

HEV. Not associated with chronic hepatitis.

18
Q

HCV immuno resistance

A

antigen variability is responsible for lack of immune response; lacks 3’-5’ proof reading activity

19
Q

non sorbitol fermenter in McKonkey’s

A

EHEC:0157

20
Q

dyptheria vaccine (DPT)

A

antigen is beta subunit of diptheria endotoxin; active immunity IgGs

21
Q

staph epidirmidis Rx

A

vancomycin

22
Q

cryptococcus infection pathogenesis

A

asymptomatic infection of lungs –> meningitis; associated with pigeon droppings

23
Q

toxoplasmosis MRI

A

ring-enhancing lessions

24
Q

Hib vaccine

A

cell wall polysacchride conjugated with diptheria or tetanus toxoid

25
Q

congenital toxoplasmosis

A

hydrocephalus, intracranial calcifications, chorioretinitis due to in-utero infection

26
Q

n. meningitidis route of entry

A

nasopharynx –> blood –> choroid plexus

27
Q

H. influenzae route of infection

A

pharynx –> lymphatics –> meninges

28
Q

pneumococcus route of infection

A

middle ear –> meninges

29
Q

viral UTI

A

adenovirus causes hemorrhagic cystitis

30
Q

subcutaneous mycosis

A

sporothrix in gardners

31
Q

interstitial pneumonia

A

CMV in AIDS patients; nuclear inclusion bodies; also atypical bugs: mycoplasma, RSV, chlamydia

32
Q

legionella associations

A

water aerosols and humidifiers

33
Q

catalase+ bugs

A

staph, pseudomonas, serratia, aspergillus, nocardia

34
Q

cold aglutinins

A

IgM antibody formed against mycoplasma and EBV; reaction with RBCs results in anemia

35
Q

types of aspergyllosis

A

invasive (neutropenic patients); colonizing (fungus ball); allergic (asthmatic patients)

36
Q

epiglotitis

A

H. influenzae; sore throat, fever, drooling, airway obstruction, stridor

37
Q

virulence factors of mycobacteria

A

sulfatides, tuberculin and serpentine cords

38
Q

Legionaire’s disease

A

high fever, pneumonia and diarrhea in a chronic smoker

39
Q

clue cells

A

squamous epithelial cells covered by Gardnerella seen on wet mount

40
Q

POMC

A

proopiomelanocorticotropin cleaved to yield ACTH, MSH and beta endorphin

41
Q

opiod receptors

A

increase gK –> decrease pain

42
Q

scotoma

A

visual field deficit surrounded by zones of normal vision indicates damage to macula in retina; retinitis pigmentosa, multiple sclerosis, diabetic nephropathy

43
Q

reperfusion arrhythmia

A

caused by tPA, reteplase, tecteplase fibrinolytic therapy

44
Q

osteoblast markers

A

LAP

45
Q

osteoclast markers

A

acid phosphatase, urinary hydroxyproline

46
Q

space constant

A

measure of the ability of an impulse to travel down an axon; low SC –> decrease impulse (ME)

47
Q

bounding femoral pulse

A

water-hammer pulse in aortic insufficiency

48
Q

pulsus parvus et tardus

A

aortic stenosis

49
Q

blood transfusions

A

contain citrate which chelates calcium and results in hypocalcemic paresthesia

50
Q

iron regulation

A

by epithelial cells of the gut and intracellular ferritin

51
Q

law of conservation of masses

A

total flow = flow velocity * cross sectional area; flow in = flow out

52
Q

AV shunt volume loop diagram

A

increased preload

53
Q

conduction velocities of heart tissue

A

AV node (0.05m/sec); ventricular muscle (0,3m/sec); atrial muscle (1.1m/sec); purkinje (2.2m/sec)

54
Q

source of ACE

A

lungs

55
Q

RV/TLC in obstructive diasese

A

increased RV more than TLC

56
Q

hypoxic vasoconstriction

A

as oxygen content decreases, arteriolar resistance increases

57
Q

perfusion-limited

A

when substances equilibrate across the membrane

58
Q

diffusion-limited

A

when substances do not equilibrate across membrane

59
Q

diffusion of oxygen

A

perfusion limited

60
Q

oxygen supplementation in COPD patients

A

COPD patients have chronic hypoxia and hypercapnia; hypoxia is main ventilatory drive so use O2 supplementation carefully

61
Q

brown adipose

A

termogenin produces heat

62
Q

pulmonary vascular resistance

A

increases as air is inhaled and on forced expiration due to increase tension of lung parenchyma

63
Q

pathophysiology of pneumoconiosis

A

fine dust particles are phagocytosed but alveolar macrophages release growth factors that stimulate fibroblast proliferation and fibrosis

64
Q

lung clearance mechanisms

A

large particles are trapped in upper respiratory tract; medium particles are cleared by mucocilliary transport; fine particles < 2.5um are phagocytosed

65
Q

causes of decreased lung compliance

A

pulmonary edema, pulmonary fibrosis, decreased surfactant, pneumoconiosses, kyphoscoliosis

66
Q

alveolar gas equation

A

PAO2 = 150 - (PaCO2/0.8); PaO2 is given value; use PAO2 to calculate A-a gradient: PAO2 - PaO2

67
Q

hypoxemia in pulmonary embolism

A

due to Va/Q mismatch

68
Q

Va/Q mismatch

A

increased A-a gradient

69
Q

hypoventilation

A

hypoxemia with normal A-a gradient

70
Q

causes of hypoxemia

A

hypoventilation, Va/Q mismatch, diffusion impairmnet, right-left shunt

71
Q

lipid absorption and digestion

A

absorption –> jejunum; digestion –> duodenum

72
Q

S4 heart sound

A

presystolic before S1; indicates decreased compliance of left ventricle

73
Q

ASD murmur

A

wide fixed S2 splitting with increased pulmonic valve pressure

74
Q

prevention of calcium stones

A

increase water intake and increase citrate which chelates calcium

75
Q

pericardial tamponade

A

muffled distant heart sounds, hypotension, increased central venous pressure and jugular regurgitation; post MI complication results in decreased venous return and hypotension

76
Q

cardiac hybernation

A

hypokalemia of heart muscle due to chronic ischemia in CAD; reversible with bypass revascularization

77
Q

ischemic preconditioning

A

resistance to infarction by myocytes exposed to chronic ischemia

78
Q

ventricular remodeling

A

adaptation in mass, volume and shape to compensate for increased hemodynamic load

79
Q

chemical mediators of atheromas

A

PDGF and TxA2 by platelets

80
Q

reperfusion injury

A

secondary to oxygen free radicals, mitochondrial damage and inflammation

81
Q

billiary tract enzymes

A

gammaglutamyl transferase and alkaline phosphatase

82
Q

liver function tests

A

PT, albumin, cholesterol

83
Q

hepatic integrity enzymes

A

AST, ALT

84
Q

alkaline phosphatase differentiation

A

if increased alkaline phosphatase, check gammaglutamyl transferase to differentiate LAP from liver AP

85
Q

aromatase

A

converts androgens to estrogens; stimulated by FSH in granulosa cells; might be deficient in female pseudohermaphrodite or elevated in male pseudohermaphrodite; inhibited by anastrozole

86
Q

cardiac contractility

A

depends on aerobic glycolysis to produce ATP and creatine phosphate; ischemia leads to loss of contractility in 30 seconds

87
Q

paradoxycal thromboembolism

A

thrombus passes from veins to arteries through an ASD; ASD produces fixed splitting of S2

88
Q

natriuretic peptide

A

synthesized by atria upon stretch and right ventricle (Brain natriuretic peptide BNP)

89
Q

cyanosis improves with squatting

A

tetralogy of fallot; increased TPR/PVR ratio increases pulmonary flow

90
Q

absence of edema in early CHF or cor pulmonale

A

because intrathroracic pressure becomes more negative (COPD, etc), venous return and lymphatic drainage increase

91
Q

holosystolic murmur

A

mitral insufficiency, tricuspid insufficiency, VSD

92
Q

S3 heart sound

A

left ventricle volume overload in CHF or mitral insuficiency

93
Q

TGF beta

A

tumor suppressor, angiogenesis, fibroblasts

94
Q

metalloproteinases

A

collagen degradation; released by macrophages; may result in rupture of atheroma and AMI

95
Q

hemodynamic changes in aortic stenosis/left ventricular hypertrophy

A

acute atrial fibrillation –> hypotension –> pulmonary edema due to decreased preload and CO

96
Q

cholestasis

A

leads to osteomalacia due to ADEK malabsorption

97
Q

Wolf-Parkinson

A

pre-excitation due to accesory bundle of Kent; delta wave on ECG, decreased PR interval and widened QRS, treat with class Ia and III antiarrhythmics

98
Q

isolated systolic hypertension

A

age related stiffening of the aorta

99
Q

aortic stenosis

A

increased left ventricle to aorta pressure gradient

100
Q

aortic insuficiency

A

palpitations due to increased stroke volume; head pounding due to high amplitude pulsations; “head bobbing” due to widened pulse pressure

101
Q

mitral stenosis murmur

A

opening snap in early diastole after aortic component of S2 (immediately after closure of aortic valve) plus diastolic murmur

102
Q

acute mitral insufficiency

A

due to rupture of cordae tendinae or prosthetic valve failure don’t have time for atrial adaptation; decreased compliance leads to pulmonary edema

103
Q

mitral stenosis severity

A

S2-to-opening snap is short –> more severe

104
Q

hepatic encephalopathy

A

decreased clearance of gut amonia by damaged liver –> increased GABA receptor activity

105
Q

gynecomastia in cirrhosis

A

decreased estrogen metabolism by liver –> gynecomastia, palmar erythema, testicular atrophy, decreased body hair

106
Q

sweat in cystic fibrosis Vs. normal people

A

normal –> hypotonic; CF –> hypertonic

107
Q

uric acid stones

A

precipitate in acid collecting ducts; Rx alkalinization of urine + hydration + indomethacin/colchicine

108
Q

squamous lung cancer paraneoplastic syndrome

A

PTH-like peptide

109
Q

RANK receptors

A

mediate osteoclast differentiation; low estrogen upregulates RANK –> increased bone resorption –> less bone mass

110
Q

why is H. pylory in duodenum

A

only colonizes gastric tissue; if present in duodenum it’s due to metaplasia

111
Q

cystic fibrosis secretions osmolarity

A

all isotonic except sweat which is hypertonic

112
Q

infectious esophagitis

A

CMV (linear ulcerations), candida (pseudomembranes), HSV-1 vesicles/ulcers

113
Q

pancreatic necrosis

A

intracellular activation of trypsin and all other proteolytic enzymes

114
Q

osteoporosis risk factors

A

smoking, menopause, corticosteroid therapy, physical inactivity, caucassian, low BMI, alcohol

115
Q

IL-5

A

associated with asthma; isotype switch to IgA

116
Q

water deprivation test

A

increased urine osmolarity if primary polydipsia; no change in diabetes insipidus

117
Q

triglycerides in insulin resistance

A

triglycerides and FFA increase insulin resistance in overweight individuals

118
Q

somatostinoma

A

inhibits all GI hormones –> billiary stones due to decreased CCK and hyperglycemia due to decreased insulin

119
Q

how does hyperprolactinemia result in osteoporosis

A

hyperprolactinemia –> hypogonadism –> decreased estrogen –> osteoporosis

120
Q

bone changes in hyperparathyroidism

A

subperiosteal thinning

121
Q

dexamethasone test

A

low dose suppress cortisol –> Cushing syndrome; high dose suppresses cortisol –> pituitary Cushing; no suppression –> ectopic ACTH

122
Q

sex hormones in bone growth

A

sex hormones promote bone growth and epipheseal closure –> short stature in spite of growth spurt

123
Q

hormonal changes with glucocorticoid therapy

A

decreased CRH, ACTH and cortisol

124
Q

hormonal changes in cryptorchidia

A

affects seminiferous tubules and Sertoli cells –> decreased inhibin and increased FSH

125
Q

hormonal changes in steroid therapy

A

increased testosterone, decreased LH and low sperm count

126
Q

Lisch nodules

A

neurofibromatosis

127
Q

Kayser-Fleischer rings

A

Wilson’s

128
Q

chromosome 8

A

c-myc

129
Q

mitochondrial diseases

A

myoclonic epilepsy, Leber, MELAS

130
Q

Friederich ataxia

A

progressive ataxia due to degeneration of spinocerebellar and dorsal column tracts, hypertrophic cardiomyopathy (50%), skeletal abnormalities, diabetes (10%), autosomal recessive

131
Q

Lesch Nyhan

A

x-linked recessive deficiency of hypoxanthine guanine phosphorybosyl transferase (HGPRT)

132
Q

heteroplasmy

A

mitochondrial inheritance shows phenotype depending on how many mitochondria patient has

133
Q

Prader-Willi deletion

A

paternal 15q deletion but affected gene is from mother

134
Q

genetic imprinting synonym

A

unisomal dysomy

135
Q

HNPCRC mutation

A

DNA mismatch repair enzyme

136
Q

Xeroderma mutation

A

DNA excision repair enzyme

137
Q

methylation

A

silences genes

138
Q

acetylation

A

activates genes; acetylation is on lysine residues

139
Q

alpha-feto protein

A

increased in neural tube defects; decreased in Down’s

140
Q

Sturge-Weber

A

port-wine stains and angiomas on the face and ipsilateral arteriovenous malformation in the meninges

141
Q

Osler-Weber-Rendu

A

hemorrhagic telangiectasia, recurrent epistaxis and GI bleeds

142
Q

Tuberous sclerosis

A

autosomal dominant; mental retardation and seizures, angiofibromas, angiomyolipoma in the kidneys (80%); rhabdomyoma in the heart

143
Q

probability that a person is a carrier if both parents are carriers

A

2 of 3

144
Q

CFTR abnormality

A

impaired posttranslational processing with subsequent degradation

145
Q

t(15,17)

A

translocation of retinoic acid receptors, no differentiation of myeloblasts

146
Q

45XO karyotype

A

due to mitotic errors after fertilization

147
Q

cystic hygroma Vs. brachial cyst

A

brachial cysts are uniloculated; hygroma has lymph tissue and are much larger (associated with Turner)

148
Q

Kallman’s syndrome

A

delayed puberty and anosmia, absence of GnRH; problem is in the hypothalamus

149
Q

G6PDH deficiency hereditary pattern

A

x-linked recessive

150
Q

22q deletion

A

DiGeorge

151
Q

antinflammatory cytokines

A

IL-10 and TGF-beta

152
Q

diabetic nephropathy drug of choice

A

ACE inhibitors and AT-1 blockers

153
Q

blood findings in ACEi therapy

A

decreased angiotensin II –> decreased GFR –> increased serum creatinine

154
Q

drugs that cause tubular necrosis

A

aminoglycosides, contrast agents, cisplatin, ampB, foscarnet

155
Q

gold therapy

A

membranous nephropathy

156
Q

determinants of volume of distribution

A

low volume of distribution: highly charged, bound to proteins, large molecular weight; large volume of distribution: drug is small and lipophylic

157
Q

pathophysiology of angina

A

heart uses most energy from beta oxidation which consumes more oxygen per ATP produced than aerobic glycolisis; fatty acid synthesis inhibitors shift energy usage from b-oxidation to aerobic

158
Q

edrophonium test

A

if symptoms improve –> myasthenia or myasthenia crisis (increase dose); if symptoms don’t improve –> cholinergic crisis (stop dose)

159
Q

lithium toxicity

A

can be caused by NSAIDs and thiazides because they increase sodium and lithium reabsorption

160
Q

on-off phenomenon

A

levodopa therapy; its unpredictable

161
Q

low MAC

A

high potency

162
Q

high solubility in blood

A

slow onset of action

163
Q

Rx bronchiolitis

A

ribavirin

164
Q

isoniazid side effects

A

vitamin B6 deficiency (sideroblastic anemia); ataxia, paresthesia, decreased pain sensation (peripheral neuropathy); hepatitis

165
Q

glucocorticoid inhalant side effects

A

oral candidiasis (treat by washing mouth)

166
Q

N-acetylcysteine

A

mucolytic used in CF; cleaves mucuous disulfide bonds

167
Q

prophylaxis of meningitis

A

rifampin

168
Q

bosentan

A

used for pulmonary hypertension; antagonist of endothelin receptors

169
Q

Leber’s optic neuropathy

A

mitochondrial inheritance; optic nerve degeneration; mutation arginine to histidine in ND4 gene affects subunit 4 of NADH dehydrogenase complex

170
Q

myoclonic epilepsy with ragged fibers

A

mitochondrial inheritance; myoclonus, seizures, ataxia, mitochondrial myopathy; ragged look of mitochondria in muscle