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USMLE Step 1 > UWorld_1.26 > Flashcards

Flashcards in UWorld_1.26 Deck (19)
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1

Consequences of renal artery stenosis/decrease of blood flow through renal artery

  • decreased blood flow ==> decreased BP sensed @ JG apparatus
    • JG apparatus = macula densa cells (sense flow/salt contect) communicate to JG cells (renin-producing cells)
  • low flow ==> increased renin production ==> increased angiotensin II production ==> aldosterone production (salt retention) + systemic vasoconstriction
  • long term renal artery stenosi ==> hyperplasia of JG cells AND/OR hypertension

2

Northern blot use

  • assessment of gene expression 
  • looks for presence of mRNA

3

Southern blot use

  • assesment for presence of DNA fragments

4

Western blot use

  • detection of proteins in a sample

5

Southwestern blot use

  • detection of DNA-bound proteins

6

Blot technique

  • samples (depending on type of test) loaded into wells and separated by size and charge using electrophoresis 
  • resultant bands transferred to nitrocellulose membrane
  • bands incubated with labeled DNA fragment, mRNA fragment or antibody to protein of interest

7

"Length constant" definition in context of nerve conduction

  • length along nerve axon that the impulse has to/can travel
  • myelination increases the length constant

8

Cellular location of heme biosynthesis

mitochondria

9

Do erythrocytes have the ability to synthesize heme?

  • Erythrocytes lose ability to make heme when they lose their mitochondrisa

10

 Positive HBsAg = 

Positive HBeAg =

  • Positive HBsAg = present after innoculation; detectable during entire symptomatic phase of Hep B
  • Positive HBeAg = indicates active viral replication

11

Positive Anti-HBsAg

  • indicates previous vaccination or clearance of HBsAg
  • positive Anti-HBsAg + positive Anti-HBcAg IgG indicates previous infection

12

Positive Anti-HBcAg IgM =

Positive Anti-HBcAg IgG =

  • IgM = acute illness
  • IgG = previous infection

13

Embryonic precursor to female reproductive structures

  • paramesonephric ducts fuse to form uterine tubes, uterus, cervix, and upper 1/3 of the vagina
  • failure of fusion of ducts ==> bicornate uterus or uterus didelphys

14

Pica presentation

  • ingestion of abnormal substances due to iron deficiency anemia
  • commonly occurs during pregnancy
  • ice is commonly consumed

15

Para-aminohippuric acid concentrations @ kidney tubules

  • some filtered at Bowman's capsule
  • majority of PAH secreted into proximal tubule
  • not reabsorbed at any portion of the tubule
  • lowest concentration @ Bowman's capsule

16

Molecular characteristics of S. pyogenes + common infections

  • gram +, cocci in chains
  • catalase -
  • beta-hemolytic (clear hemolysis)
  • pyr-positive
  • common infections
    • pharyngitis
    • necrotizing fascitis

17

Types of shistosoma species + syndromes

  • schistoma = due to consumption of water contaminated w/snails
  • S. haematobium
    • common in Africa, middle east
    • ==> urinary schistomiasis
  • S. mansoni
    • common in Africa, middle east, South America
    • ==> intestinal schistosomiasis
  • S. japonicum
    • common in asia, phillipines
    • ==> hepatic schistosomiasis

18

Common molecular deficit in neurodegeneritive disorders

disorder of ubiquitination pathway ==> protein accumulation ==> alzheimer's and parkinson's

19

Common procedure to prevent emboli from DVT

IVC filter placement

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