UWorld_1.26

Question 1

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

Answer 1

• 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

Question 2

Northern blot use

Answer 2

• assessment of gene expression
• looks for presence of mRNA

Question 3

Southern blot use

Answer 3

• assesment for presence of DNA fragments

Question 4

Western blot use

Answer 4

• detection of proteins in a sample

Question 5

Southwestern blot use

Answer 5

• detection of DNA-bound proteins

Question 6

Blot technique

Answer 6

• 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

Question 7

“Length constant” definition in context of nerve conduction

Answer 7

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

Question 8

Cellular location of heme biosynthesis

Answer 8

mitochondria

Question 9

Do erythrocytes have the ability to synthesize heme?

Answer 9

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

Question 10

Positive HBsAg =

Positive HBeAg =

Answer 10

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

Question 11

Positive Anti-HBsAg

Answer 11

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

Question 12

Positive Anti-HBcAg IgM =

Positive Anti-HBcAg IgG =

Answer 12

• IgM = acute illness
• IgG = previous infection

Question 13

Embryonic precursor to female reproductive structures

Answer 13

• 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

Question 14

Pica presentation

Answer 14

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

Question 15

Para-aminohippuric acid concentrations @ kidney tubules

Answer 15

• 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

Question 16

Molecular characteristics of S. pyogenes + common infections

Answer 16

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

Question 17

Types of shistosoma species + syndromes

Answer 17

• 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

Question 18

Common molecular deficit in neurodegeneritive disorders

Answer 18

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

Question 19

Common procedure to prevent emboli from DVT

Answer 19

IVC filter placement