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USMLE Step 1 > UWorld_3.18 > Flashcards

Flashcards in UWorld_3.18 Deck (21)
1

Medications that cause fat redistribution

  • glucocorticoids
  • HAART
  • fat from extremities ==> abdominal viscera and subcuatneous adipose tissues of the thorax, postererior neck, and supraclavicular region

2

thiopental: moa, use

  • lipid-soluble barbituate used as short-term anesthesia
  • ==> brain ==> rapid redistribution to skeletal muscle and adipose tssue (w/in 5-10min)
    • rapid redistribution allows for short term anesthia

3

Reason for measuring phospholipids in amniotic fluid

  • helps asses fetal lung maturity
  • phospholipids i.e. dipalmitoyl phosphatidylcholine (lecithin) = major component of pulmonary surfactant
  • L (lecithin)/ S (sphingomyelin) ratio used tp asses maturity
    • L/S > 2 = mature

4

Left testicular vein ==>

right testicular vein ==>

  • left ==> left renal vein
  • right ==> IVC

5

Hyperammonemia in hepatic encephalopathy ==> biochemical consequences?

  • depletion of alpha-ketoglutarate ==I kreb's cycle
  • excess ammonia also depletes glutamate (excitatory NT) ==> glutamine accumulation ==> astrocyte swelling and dysfxn

6

Patient receives >5-6L of whole blood/RBCs over 24 hours ==>

  • elevated levels of citrate (anticoagulant)
  • citrate chelates calcium and magnesium ==> paresthesias

7

Consequence of verapamil on cardiac pacemaker cells

  • verapamil = ca-channel bloccker
  • ==> slowed depolarization at phase 0 and end of phase 4
  • "slow diastolic depolarization"

8

Glucose transporters that are responsive to insulin

  • ONLY GLUT 4 @ skeletal muscle and adipose tissue

9

MS vs. MR murmur

  • MS = opening snap + low-pitched, mid-diastolic rumbing murmur heard at apex
  • MR = blwing, holosytolic murmur; heard at apez and radiates to axilla

10

Lung cancer that cannot usually be treated with surgery

  • small cell carcinoma
  • most aggressive; usually distant mets @ discovery
  • responsive to chemotherapy and radiation

11

HLA class I =

HLA class II = 

  • class I =
    • HLA-A, HLA-B, HLA-C
    • genes that code for MHC I receptors on all body cells
  • class II = 
    • HLA-DR, HLA-DQ
    • genes that code for MHC II receptors on immune cells

12

Characteristics of serotonin syndrome

  • occurs when SSRIs are given in conjunction w/other serotonergic agens
  • sx
    • neuromuscular excitation: hyperreflexia, clonus, myoclonus, rigidity
    • autonomic stimulation: hyperthermia, tachycardia, diaphoresis, tremor
    • AMS

13

Examples of serotonergic agents

  • Anti-depressants 
    • monoamine oxidase inhibitors
    • TCA
    • SNRI
  • analgesics
    • tramadol
  • anti-emetics
    • 5-HT3 receptor antagonists (ondansetron)
  • antibiotics
    • linezolid = weak monoamine oxidase inhibitor
  • neuropsych
    • triptans

14

Presentation and mechanism of normal pressure hydrocephalus

  • elderly patients
  • ==> ataxic gait, urinary incontinence, dementia
  • sx due to distortion of periventricular white matter

15

Regulations of mictrurition

  • sacral mictrution center = S2-S4 level and ==> bladder contraction
    • parasym fibers travel from S2-S4 ventral white matter @ pelvic nerves to stimulate cholinergic receptors in bladder wall
  • pontine micturition center = @ pontine reticular formation.
    • coordinates relaxation of external urethral sphincter w/bladder contraction during voiding
  • cerebral cortex = inhbits sacral micturition center

16

Tx tp prevent recurrences of genital herpes

  • daily treatment with oral valacyclovir, acyclovir, or famciclovir ==> suppression of reactivation

17

Consequences of T. cruzi infection

  • destroys myenteric plexus @:
    • esophagus ==> achalasia
    • intestines ==> megacolon
    • ureters ==> megaureter
  • dilated cardiomyopathy

18

abd pain and distention + fever + diarrhea + signs of shock + hx of IBD ==> dx?

  • toxic megacolon <== dx via abdominal xray

19

Amphotericin B: MOA, SE

  • MOA = binds ergosterol ==> pores ==> cell death
  • SE
    • renal toxicity
    • ==> vasoconstrict ==> decreased GFR 
    • direct toxin to renal epithelial cells ==> ATN, renal tubular acidosis, and electrolyte distrubances
      • **hypoK and hypoMg <== usually supplemented during tx
    • ==> decreased EPO ==> normochromic, normocytic anemia

20

Water-soluble vit with significant body stores

Vit B12; can last years with absence in diet

21

Characteristics of follicular (non-hodgkin's lymphoma)

  • aggregates of packed follices that obscure normal lymph node architecture
  • t(14;18) ==> overactive BCL-2 gene

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