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Flashcards in UWorld Final Run Deck (189):
1

Systemic mastocytosis

  • Abnormal mast cell proliferation
  • Increased histamine release
  • Parietal cell gastric acid hypersecretion
  • HypOtension, flushing, pruritis

2

Decreased O2 delivery to tissues causes what?

  • Left shift of Hb dissociation curve
  • Compensatory erythrocytosis from renal hypOperfusion

3

Drug that increases QT at higher heart rates

Class IC Antiarryhthmics

4

Drug that increases QT at slower heart rates

Class III Antiarrhythmics

5

5 receptors that mediate vomiting

  • M1
  • D2
  • H1
  • 5-HT3
  • NK1

6

mechanism of extended-spectrum beta-lactamase resistance

plasmid transfer

7

Hawthorne Effect

tendency of study subjects to change behavior as a result of awareness of being studied

8

most common defect in paradoxical embolization

PFO (lack of fusion of septum primum + secundum)

9

Arginase deficiency

  • Normally converts arginine → urea + ornithine
  • Causes spastic diplegia, growth delay, and abnormal movement
  • Elevated arginine w/NO hyperammonemia
  • Rx: low-protein diet

10

IgE class switching cytokine

IL-4

11

IgA class switching cytokine

IL-5

12

eosinophil activating cytokine

IL-5

13

mu receptor MOA

  • G-protein linked
  • increase K+ efflux

14

sebaceous gland secretion mechanism

holocrine (cell lysis → release of entire contents of cytoplasm + cell memb)

15

mammary gland secretion mechanism

Apocrine (membrane-bound vesicles)

16

Sweat gland secretion mechanism

Merocrine (exocytosis)

17

3 major portosystemic anastomoses

  1. L Gastric vv → Esophageal vv → Esoph Varices
  2. Superior Rectal vv → Middle + Inferior Rectal vv → Hemorrhoids
  3. Paraumbilical vv → Superficial + Inferior Epigastric vv → Caput Medusae

18

COX-2

  • inducible enzyme
  • undetectable in most tissues unless inflammatory activation present

19

Chloride shift

  • To carry CO2 from tissues, RBC carbonic anhydrase forms bicarb, which diffuses out into plasma
  • Chloride ions diffuse into RBC to maintain electrical neutrality
  • Principal cause of high RBC chloride content in venous blood

20

Major basic protein

  • released by eosinophils
  • kills helminths
  • contributes to bronchial epithelial damage in atopic asthma

21

L frontal lobe lesion

apathy, depression

22

R frontal lobe lesion

disinhibited behavior

23

corpus callosum lesion

  • "split-brain" syndrome
  • lack of interhemispheric transfer of info
  • unable to retrieve w/one hand an object palpated w/other

24

non-dominant parietal lobe lesion

  • hemineglect
  • constructional apraxia

25

dominant parietal lobe lesion

  • Gerstmann synd
  • R-L confusion
  • Agraphia
  • Acalculia

26

Temporal lobe lesion

  • language disturbances
  • sensory interpretation disturbances
  • impaired memory
  • hyperorality
  • hypersexuality

27

Filtration fraction eqn

FF = GFR / RPF

28

Temporomandibular d/o

  • Problems w/TM joint, mm of mastication, and/or jaw nn
  • Mandibular division of trigeminal nn supplies mm of mastication + middle ear → jaw pain + otologic symp

29

Drugs that preferentially bind to ischemic myocardial tissue

Class IB Antiarrhythmics

  • primarily bind to Na+ channels in inactivated state
  • effective in suppressing ventricular arrhythmias during MI

30

blotchy red mm fibers on Gomori trichrome stain

mitochondrial myopathy

31

insulin resistance

  • acanthosis nigricans
  • lipolysis → FFA release
  • Inc FFA levels → impaired insulin-dependent glucose uptake in liver + mm and increased hepatic gluconeogenesis

32

Safe site for gluteal injection

Anterolateral region/von Hochstatter Triangle or Superolateral quadrant

  • superomedial quadrant risks superior gluteal nn injury
  • superomedial, inferomedial, and inferolateral regions risk sciatic nn injury

 

33

mechanism of phenytoin-induced gingival hyperplasia

increased PDGF → gingival macrophages stimulate prolif of gingival cells + alveolar bone

34

Homocystinuria

  • Cystathionine synthase defect
  • Inability to form cysteine from homocysteine → elevated homocysteine + methionine
  • Premature thromboembolic events, hypERcoagulability, ectopia lentis, intellectual disability

35

Alkaptonuria

  • AR deficiency in homogentisic acid dioxygenase (tyrosine metabolism)
  • Excess homogentisic acid
  • Blue-black deposits in connective tissue, osteoarthropathy of spine/large joints

36

Glomus tumor

  • very tender, small, red-blue lesion under nail bed
  • originates from modified smooth mm cells that control thermoregulatory fcns of dermal glomus bodies

37

HPV likes to infect what tissue?

stratified squamous epithelium

  • true vocal cords
  • cervix
  • anus

38

false vocal cords

folds of mucus membrane lined in respiratory epithelium (ciliated pseudostratified columnar w/goblet cells)

39

Low volume of distribution

3-5L: plasma compartment

  • High molec weight
  • High plasma protein binding
  • High charge
  • Hydrophilicity

40

High volume of distribution

41L: intracellular compartment

  • Small molec weight
  • Uncharged
  • Lipophilic

41

HTN drug that can cause peripheral edema

DHP CCBs

42

nucleolus

  • primary site of ribosome synthesis + assembly
  • transcribes all rRNA except 5S

43

McArdle Disease

  • Myophosphorylase deficiency
  • Failure to cleave alpha-1,4 glycosidic linkages → failure to convert mm glycogen to glucose-1-phosphate
  • Poor exercise tolerance, mm cramps, rhabdomyolysis/Mb-uria

44

Molecules involved in inflammatory leukocyte accumulation

  1. Margination: increased vascular leaking
  2. Rolling:
    • Neutrophil Sialyl Lewis X / PSGL-1
    • Endothelial cell P/E-selectin
  3. Activation: slow rolling → integrin activation
  4. Tight adhesion:
    • Neutrophil CD18 → Mac1, LFA1 (def = LAD)
    • Endothelial cell ICAM-1
  5. Transmigration: Endothelial cell PECAM-1

45

Thyroidectomy puts what nn at risk

external brr of superior laryngeal nn (runs w/superior thyroid aa)

  • cricothyroid mm → hoarseness

46

Lesch-Nyhan

  • XLR defect in HGPRT (purine salvage)
  • Increased uric acid
  • Increased PRPP amidotransferase activity (de novo purine synth)
  • Delayed development, dystonia, choreoathetosis, self-mutilation, hyperuricemia

47

best indicator of severity of mitral regurg

presence of S3

48

Lactase deficiency labs

  • increased breath H+
  • decreased stool pH
  • increased stool osmotic gap

49

elevation in leads I and aVL

Left circumflex aa occlusion

50

NOD2 gene mutation

Crohns

decreased NF-kB production → decreased cytokine production

51

insulitis

 leukocyte infiltration of pancreatic islet cells

seen in Type I DM

52

MECP2 mutations

Rett Synd

53

characteristics of CXR in acute decompensated heart failure

  1. Cephalization of pulmonary vessels
  2. Perihilar alveolar edema
  3. Blunting of costophrenic angles (effusion)
  4. Kerley B lines (interlobular septa edema)

54

osteoclast activity markers

  1. urinary deoxypyridinoline (most reliable)
  2. urinary hydroxyproline
  3. tartrate-resistant acid phosphatase

55

axonal reaction

changes in neuron body after severed axon → reflect increased protein synth that facilitates axon repair

  • enlarged, rounded cell
  • peripherally-located nuclei
  • dispersed, finely granular Nissl substance

56

ear innervation

  • Vagus small auricular brr: posterior external auditory canal
  • Trigeminal mandibular div: rest of canal

57

enzyme that provides substrates for gluconeogenesis and ketone prod during starvation

Hormone-sensitive lipase (TG → FFA + glycerol)

58

non-inflammatory dimpling of overlying skin in breast cancer signifies infiltration of what structure?

suspensory ligament

59

Myotonic Dystrophy

AD disorder w/trinucleotide repeats on MPK gene

  • sustained mm contraction
  • weakness / atrophy
  • cataracts
  • frontal balding
  • gonadal atrophy

60

Connexins

gap junctions

61

Claudins

tight junctions

62

Occludins

tight junctions

63

Cadherins

  • Adherens junctions
  • Desmosomes

64

Integrins

transmembrane anchor proteins

Hemidesmosomes

65

Osmium tetroxide stain

stains fat black

66

phenotype with 46,XY and total absence of Sertoli cells

  • Lack of mullerian inhibiting factor → female internal genitalia
  • Normal testosterone → male internal genitalia
  • Normal DHT production → male external genitalia + prostate

67

NMDA receptor antagonism

increased release of excitatory NTs

68

Secretin

  • From duodenal S cells
  • Response to increasing H+ concentration
  • Increases pancreatic HCO3- secretion
  • Proportionally decreases pancreatic Cl- secretion

69

Abx effective against Pseudomonas

  1. Piperacillin/Ticarcillin
  2. Ceftazidime
  3. Cefepime
  4. Amikacin/Gentamicin/Tobramycin
  5. Ciprofloxacin/Levofloxacin
  6. Imipenem/Meropenem
  7. Aztreonam

70

Allergic bronchopulmonary aspergillosis

  • HS rxn in pts w/asthma or CF
  • High IgE
  • Eosinophilia
  • Airway inflamm + mucus plugging w/exacerbations and remissions
  • Transient pulmonary infiltrates
  • Proximal bronchiectasis

71

Photoaging

  • Excess UVA exposure
  • Epidermal atrophy w/flattening of rete ridges
  • Decreased collagen fibril production
    • But increased crosslinking!
  • Increased degradation of collagen and elastin in dermis

72

Zidovudine MOA

  • Nucleoside reverse transcriptase inhibitor (competitive) incorporated into viral genome as thymidine analog
  • Prevents DNA chain elongation: lack of 3' OH group makes 3'-5' phosphodiester bond formation impossible

73

Hep A presentation

  • Fever/malaise
  • Anorexia
  • Nausea/vomiting
  • RUQ pain
  • Cholestasis
    • jaundice
    • pruritis
    • dark urine
    • clay-colored stool

74

Nitrate S/E

  • Throbbing HA
  • Cutaneous flushing
  • Lightheadedness
  • HypOtension
  • Reflex tachycardia

75

Pulsion diverticula

  • Often involve sigmoid colon
  • Due to increased intraluminal pressure (pulsion) during strained bowel movements
  • Outpouching of mucosa and submucosa
  • May present w/hematochezia or diverticulitis

76

Traction diverticula

  • Created by inflamm and subsequent scarring of gut wall
  • Results in pulling and outpouching of all layers of wall → true diverticula
  • May occur in mid-esophagus due to mediastinal lymphadenitis (TB, fungal infxn)

77

1st generation antihistamines

  • Chlorpheniramine
  • Diphenhydramine
  • Promethazine
  • Hydroxyzine

78

Ladd's bands

intestinal malrotation → connect retroperitoneum in RLQ to right colon/cecum by passing over 2nd part of duodenum → obstruction

79

Pulmonary fibrosis features

Can be caused by interstitial lung disease

  • Decreased FVC
  • Normal/increased FEV1/FVC
  • Increased lung elastic recoil
  • Radial traction (outward pulling) by fibrous tissue → airway widening

80

Telomerase

  • Ribonucleoprotein
  • RNA-dependent DNA polymerase
  • Reverse transcriptase activity
  • Adds TTAGGG repeats to 3' end of chromosomes
  • Expressed in stem cells (i.e. epidermal basal cells)

81

Left shift of Hb curve

Increased Hb affinity for O2 → more O2 to lungs, less to tissues

  • Decreased H+ (alkalosis)
  • Decreased 2,3-BPG
  • Decreased temp
  • Decreased CO2

82

Right shift of Hb curve

Decreased Hb affinity for O2 → more O2 to tissues, less to lungs

  • Increased H+ (acidosis)
  • Increased 2,3-DPG (chronic lung disease, HF, chronic high altitude)
  • Increased temp
  • Increased CO2

83

bisphosphoglycerate mutase

  • Enzyme unique to RBCs
  • Converts 1,3-BPG → 2,3-BPG (hypoxia, chronic anemia)
    • Allows bypass of 1,3-BPG → 3-PG in glycolysis w/NO production of ATP

84

Bisphosphonate MOA

  • Chemical structure similar to pyrophosphate
  • Attach to hydroxyapatite binding sites on bony surfaces (preferentially in areas of high turnover)
  • Decrease osteoclast activity (induce apoptosis and decrease development of precursors)

85

Trochlear nn palsy

Superior oblique problem

  • Vertical diplopia
  • Impairment of downgaze with eye adducted
  • "Down and out"
  • Head tilt away from affected eye

86

Kegel exercises

strengthen levator ani

87

Hep C virus genetic variation

  • Lacks proofreading 3'→5' exonuclease activity in RNA polymerase
  • Envelope glycoproteins contain hypervariable region prone to frequent mutation

88

Mannitol

  • Osmotic diuretic
  • Increased plasma/tubular fluid osmolality → water extraction → diuresis
  • Can help reduce ICP in cerebral edema
  • S/E:
    • pulmonary edema
    • metabolic alkalosis
    • hypERkalemia

89

Orotic aciduria

  • AR defect in UMP synthase (pyrimidine synthesis)
  • Findings:
    • Physical + mental retardation
    • Megaloblastic anemia
    • Elevated urinary orotic acid
    • NO hyperammonemia
  • Rx: uridine supplementation (bypasses enzyme)

90

Gaucher disease

  • AR deficiency in beta-glucocerebrosidase
  • Findings:
    • Pancytopenia
    • Hepatosplenomegaly
    • "Tissue paper" macrophages (Gaucher cells)

91

Ubiquitin ligase

Recognizes specific protein substrates and attaches ubiquitin tag

  • Proteins then degraded and coupled to MHC I in ER
  • Presented on cell surface to CD8 cells

92

SMA syndrome

  • diminished mesenteric fat OR pronounced lordosis OR surgical correction of scoliosis →
  • critical decrease in aortomesenteric angle →
  • transverse portion of duodenum entrapped btwn SMA and aorta → partial obstruction

93

which part of intestine is always involved in Hirschsprung?

rectum and anus

94

polycistronic mRNA

  • can be seen in bacterial mRNA
  • one mRNA codes for several proteins
  • ex: lac operon → codes for proteins necessary for lactose metabolism
    • single promoter, operator, and set of regulatory elements

95

burning suprapubic pain after abdominal sx

iliohypogastric nn injury

  • sensation to suprapubic and gluteal regions
  • motor to anterolateral abd wall mm

96

Genitofemoral nn

  • L1-L2 roots
  • sensation to upper anterior thigh
  • motor to parts of genitalia (cremasteric reflex)

97

Ilioinguinal nn

  • L1 root
  • accompanies spermatic cord thru superficial inguinal ring
  • sensation to upper and medial thight and parts of external genitalia

98

free ribosomes

  • remain floating in cytosol throughout protein synth
  • translate proteins found in cytosol, nucleosol, peroxisome matrix, and nuclear-encoded mitochondrial proteins

99

attached ribosomes

  • bind to RER after translation begins via translocons (protein complexes containing ribophorins)
  • synthesize secretory proteins, membrane proteins, and proteins within ER / Golgi / lysosomes

100

foreign body in piriform recess

  • may damage internal laryngeal nn (branch of superior laryngeal nn, CN 10)
  • impaired cough reflex

101

in absence of ADH, urine is most concentrated and most dilute in which parts of nephron?

  • Most concentrated: junction btwn descending and ascending Loop of Henle
  • Most dilute: collecting ducts

102

Progression of neuron injury

  • 12-24h: "red neurons" w/loss of Nissl substance
  • 24-72h: neutrophils
  • 3-7d: macrophages and microglia
  • 1-2wk: reactive gliosis, vascular prolif → liquefactive necrosis
  • 2+wk: glial scar formation

103

West Nile virus

  • Pos sense ssRNA flavivirus
  • Culex mosquito vector
  • Dx: CSF anti-WNV Ab's
  • Findings:
    • Fever
    • Rash
    • Flaccid paralysis
    • Encephalitis

104

Case-Control Study

  • Retrospective
  • ID risk factors given existing disease (or lack thereof)
  • Gives Odds Ratio = [A/C] / [B/D]

105

Cohort Study

  • Retrospective OR Prospective
  • ID outcome of interest given risk factors
  • Gives Relative Risk or Risk Ratio = [A/A+B] / [C/C+D]

106

Cross-Sectional Study

  • People w/disease or risk factor at certain time
  • ID prevalence

107

Attributable risk percent in exposed

Excess risk in exposed population that can be attributed to risk factor

ARPE = 100 x [(RR-1) / RR]

108

Alanine function

  • Nitrogen transfer to liver for disposal
  • Source of carbon skeletons for gluconeogenesis
  • Protein catabolism:
    • amino groups transferred to alpha-ketoglutarate → glutamate
    • Liver: glutamate → urea

109

Thiamine is a cofactor for these 4 enzymes

  1. Pyruvate dehydrogenase
  2. Alpha-ketoglutarate dehydrogenase
  3. Branched chain alpha-ketoacid dehydrogenase
  4. Transketolase

110

Restless leg syndrome

  • Uncomfortable sensation in legs + urge to move them
  • Worse at rest and when falling asleep
  • Rx: DA agonists (ropinirole, pramipexole)

111

Treatment for neonatal pulmonary HTN that may cause methemoglobinemia

Inhaled nitric oxide

112

Myotonia

abnormally slow mm relaxation (i.e. sustained contraction)

113

Ab with high specificity for RA

Anti-citrullinated peptide

114

what limits max combined sensitivity and specificity of a test?

degree of overlap btwn healthy and disease population curves

115

umbilical hernia

  • incomplete closure of umbilical ring
  • reducible
  • asymptomatic
  • most resolve spontaneously
  • assoc w/
    • Down synd
    • HypOthyroidism
    • Beckwith-Wiedemann synd (overgrowth)

116

stool findings in cholera

mucus + sloughed epithelial cells

117

Pathogens causing inflammatory diarrhea

Invasion or Cytotoxin → fecal leukocytes +/- RBCs

  • Shigella
  • Salmonella
  • Campylobacter
  • E. coli (enteroinvasive)
  • C. diff
  • Entamoeba

118

Pathogens causing non-inflammatory diarrhea

Enterotoxin → no fecal leukocytes or RBCs

  • V. cholerae
  • E. coli (enterotoxigenic)
  • B. cereus
  • S. aureus
  • some viruses
  • Giardia
  • Cryptosporidium
  • Cyclospora
  • Microsporidia

119

Diarrhea w/fecal leukocytes w/monocytic predominance

S. typhi → typhoid fever

120

erosion

mucosal defect that does not extend completely through muscularis mucosa

121

ulcer

extends into submucosa and muscularis propria

122

patellar reflex nerve root

L4

123

achilles reflex nerve root 

S1

124

nerve roots in lumbosacral spine exit foramina where?

BELOW corresponding vertebral body level (i.e. compression btwn L5-S1 affects L5 root)

125

rib vessels run where?

INFERIOR to rib

126

L5 radiculopathy

  • back pain radiating down leg
  • sensory loss over buttocks, lateral thigh, lateral calf, and dorsal foots
  • weakness on foot dorsiflexion, inversion, eversion, and toe extension

127

S1 radiculopathy

  • sensory loss over buttocks, posterior thigh, posterior calf, and lateral foot
  • weakness on hip extension, knee flexion, foot plantarflexion, and Achilles reflex

128

ADH increases reabsorption of what 2 substances?

H2O and urea (via V2 receptor) in collecting duct

129

kinesin

MT-assoc motor protein that moves ANTerograde (away from nucleus, down axon), powered by ATP

kinesin "kicks" it forward

130

dynein

MT-assoc motor protein that moves RETROgrade, toward nucleus

dynein "draws" it back

131

fibrates

  • MOA:
    • inhibit cholesterol 7-alpha hydroxylase (rate-limiting enzyme in bile acid synth)
    • Activate PPAR-alpha
    • Decrease VLDL synth
  • Therapy: Decrease TGs
  • S/E: gallstones, myopathy

132

effects of ischemia on ion pumps

Decreased OXPHOS → decreased ATP → decreased activity of:

  • Membrane Na+/K+ ATPase → increased intracellular Na+ and extracellular K+
  • Sarcoplasmic reticulum Ca2+ ATPase → increased intracellular Ca2+

133

substance decreased in CSF in narcolepsy

Hypocretin-1 / Orexin (lateral hypothalamus)

134

statins

  • Inhibit HMG-CoA Reductase (rate-limiting cholesterol synth)
  • Therapy: Decrease LDL
  • S/E: Hepatotoxicity, myopathy

135

Niacin

  • MOA:
    • Decrease FA release
    • Decrease VLDL synth
    • Decrease HDL clearance
  • Therapy: Increase HDL
  • S/E: Flushing, hepatotoxicity, gout

136

Pulsus paradoxus

  • Exaggerated drop in SBP during inspiration
    • Detect by inflating cuff above SBP and slowly deflating → difference btwn pressure at which sounds first become audible during expiration and pressure at which they are heard throughout all phases of respiration
  • Most often:
    • Pericardial disease
    • COPD/asthma

Remember: inspiration increases vv return

137

Rx COPD exacerbation

Beta-blockers

138

hereditary fructose intolerance

  • Aldolase B deficiency
  • Accumulation of Fructose-1P → impaired gluconeogenesis → hypoglycemia and vomiting
  • Restrict fructose and sucrose from diet

139

melanocytic nevus

  • benign neoplasm
  • round, uniform melanocytes that are mitotically quiescent
  • maturation:
    • Junctional nevus: melanocytes along derm-epiderm jct; flat
    • Compound nevus: extends into dermis; raised
    • Intradermal nevus: dermis only; produce little to no pigment; skin-colored and dome-shaped

140

most common cause of viral gastroenteritis

norovirus

141

homeobox

  • highly conserved DNA sequence 180bp in length
  • gene containing this sequence = hox gene
  • code for TFs that bind to DNA regulatory regions
  • alter expression of genes involved in segmental organization (cranial-caudal) of embryo

142

cleft lip

maxillary prominence fails to fuse with intermaxillary segment during 5-6wk of development

143

cleft palate

palatine shelves fail to fuse with one another OR with primary palate

144

failure of medial nasal prominence to fuse

severe midline defects (holoprosencephaly)

145

acute compartment syndrome

  • increased pressure w/i fascial compartment → impaired perfusion
  • severe pain, myonecrosis, nn injury
  • most often: leg anterior compartment
    • contains deep fibular nn and anterior tibial aa + vv

146

sorbitol metabolism

  • Glucose → Sorbitol
    • by Aldose Reductase + NADPH
  • Sorbitol → Fructose + NADH
    • by Sorbitol Dehydrogenase

147

acute ureteral constriction/obstruction

decreased GFR

decreased RPF

decreased FF

148

Findings in infant born to HBeAg+ mother

  • high levels of HBV replication
  • HBeAg+
  • asymptomatic/mild symptoms
  • high risk for chronic infxn (cirrhosis/HCC)
    • administer HBV vaccine + immune globulin immediately after delivery to prevent

149

Zenker diverticulum

  • abnl spasm/diminished relaxation of cricopharyngeal mm during swallowing
    • early oropharyngeal dysphagia
  • increased pressure → eventual herniation of pharyngeal mucosa thru Kilian triangle (false diverticulum)
    • food rentention w/halitosis or regurgitation
    • pulmonary aspiration

150

PAH

can be used to approximate RPF

  • freely filtered
  • secreted primarily by proximal tubule
  • not reabsorbed → steadily increasing concentration thru nephron

151

heme oxygenase

converts heme → biliverdin

causes bruises to turn green

152

direct arteriolar dilators

hydralazine, minoxidil

  • Rx HTN
  • reflex SNS activation via baroreceptor stimulation
    • increased HR, contractility, output
    • RAA system stimulation → Na+ and fluid retention w/peripheral edema
  • give w/sympatholytics and/or diuretics to limit S/E

153

hypertensive vasculopathy

  • involves small penetrating brr (lenticulostriate) of major cerebral aa
  • charcot-bouchard aneurysms
  • most common cause of spontaneous deep intracerebral hemorrhage
  • most often affects:
    • basal ganglia (putamen)
    • cerebellar nuclei
    • thalamus
    • pons

154

basal ganglia hemorrhage

  • HTN vasculopathy
  • lenticulostriate aa
  • involvement of post limb internal capsule→ contralat hemiparesis and hemianesthesia
  • expansion → HA, N/V, altered mental status
  • may see midline shift

155

HIV-associated dementia

  • progressive cognitive decline
  • microglial nodules: groups of activated macrophages/microglial cells around small areas of necrosis
  • may fuse to form multinucleated giant cells

156

Combined OCP mechanism of action

suppress GnRH and pituitary gonadotropin secretion → inhibition of ovulation

157

Progestin OCP mechanism of action

thickened cervical mucus → impaired sperm penetration

158

Copper IUD mechanism of action

chronic cytotoxic inflamm response in uterus → impaired sperm migration

159

Ketogenic AAs

lysine

leucine

160

Cerebellar vermis

  • axial/truncal posture and coordination
  • connections w/medial descending motor systems
  • lesion:  truncal ataxia

161

Vestibulocerebellum

  • flocculonodular lobe
  • balance and ocular movements
  • conections w/vestibular nuclei and MLF

162

Cerebellar hemispheres

  • motor planning (lateral) and execution (intermediate)
  • lateral descending motor systems
  • lesion: dysmetria, intention tremor

163

ulnar nn injury

  • sensory loss in medial 1 1/2 digits
  • ulnar claw
  • weakness:
    • wrist flexion
    • wrist aDduction
    • finger aB/aDduction
    • 4th/5th digit flexion

164

median nn injury

  • sensory loss in 1st-3rd digits
  • hand of benediction
  • weakness:
    • wrist flexion
    • wrist aBduction
    • 2nd/3rd digit flexion
    • thumb flexion
    • thumb opposition

165

stop codons

  • UAA, UAG, UGA
  • ribosome encounters → releasing factor proteins bind to ribosome → release of polypeptide chain + dissolution of ribosome-mRNA complex

 

166

snRNPs

remove introns from pre-mRNA (splicing)

167

how does increased estrogen affect thyroid function?

increased TBG levels → increased total thyroid hormone (T4 and T3) levels but normal free hormone levels

168

dengue fever

  • ssRNA flavivirus
  • 4 serotypes
  • primary infxn: asymptomatic or self-limited disease
  • secondary infxn: different serotype → more severe illness

169

GTP production in TCA cycle

Succinyl-CoA → Succinate by Succinyl-CoA Synthase

*GTP used in gluconeogenesis for Oxaloacetate → PEP by PEP carboxykinase

170

carotid sinus

  • dilation of ICA located just above bifurcation of common carotid
  • afferent: baroreceptors → CN 9 → vagal nucleus and medullary centers
  • efferent: PSNS impulses via CN 10

171

which cells release proteinases that damage the lung?

neutrophils + alveolar macrophages

172

most common predisposing condition for native valve infective endocarditis

developed nations: MVP

developing nations: rheumatic heart disease

173

attrition bias

  • form of selection bias
  • disproportionate loss to follow-up btwn exposed and unexposed groups

174

Hartnup disease

defective intestinal and renal tubular absorption of neutral aromatic AAs → excess dietary loss of tryptophan → niacin deficiency

175

congenital hypothyroidism

asymptomatic at birth (maternal T4)

  • constipation
  • lethargy
  • hypotonia
  • macroglossia
  • umbilical hernia
  • large anterior fontanelle

176

env gene

  • encodes polyprotein precursors
  • glycosylated to gp160
  • proteolytically cleaved in ER/Golgi to gp120 and gp41

177

biotin

CO2 carrier on surface of carboxylase enzymes

  • Pyruvate carboxylase (Pyruvate → Oxaloacetate) gluconeogenesis
  • ACoA carboxylase (ACoA → Malonyl-CoA) FA synth
  • Priopionyl-CoA carboxylase (Propionyl-CoA → Methylmalonyl-CoA) FA oxidation

178

Osgood-Schattler disease

  • repetitive quadriceps contraction → overuse injury at secondary ossification center of tibial tubercle (patellar ligament insertion)
  • focal pain and swelling at tibial tuberosity

179

contralateral homonymous hemianopia

optic tract lesion

180

Marcus Gunn pupil

  • optic tract lesion
  • relative afferent pupillary defect
  • pupil contralateral to lesion appears to dilate w/light on swinging flashlight test

181

elastin

  • Large polypeptide precursor w/mostly nonpolar AAs
  • Non-hydroxylated proline and lysine residues
  • rubber-like properties: extensive desmosine cross-linking btwn monomers, facilitated by lysyl oxidase in extracellular space

182

isoniazid MOA

  • Inhibits pyridoxine phosphokinase → Vit B6 deficiency
  • Lack of B6 → inhibition of ALA Synthase (rate-limiting in heme synth)
  • Sideroblastic anemia

183

interscalene nn block

  • Anesthetizes brachial plexus as it passes thru scalene triangle → anesthesia for shoulder and upper arm
  • Involvement of phrenic nn roots passing thru interscalene sheath → transient ipsilateral diaphragmatic paralysis

184

Lynch Syndrome / HNPCC gene mutations

DNA mismatch repair genes

  • MSH2
  • MLH1
  • MSH6
  • PMS2

185

S. aureus Protein A

  • Virulence factor in cell wall
  • Binds to Fc portion of IgG
  • Impairs complement activation, opsonization, and phagocytosis

186

gonadal arteries

  • arise from abdominal aorta slightly below renal aa
  • obstructed in testicular torsion

187

diuretics than can improve survival in pts w/CHF and decreased LV EF

  • Mineralocorticoid receptor antagonists (spironolactone, eplerenone)
  • Avoid in pts w/hyperkalemia or renal failure

188

Nystatin MOA

binds ergosterol in fungal cell membrane and forms pores (also Ampho B)

189

resistance MOA for MRSA

altered PBPs