3/2 UWORLD test #29

Question 1

Q 1. How splenic laceration causes shoulder pain?

Answer 1

abdominal irritation -> phrenic nerve innervating diaphragm -> C3-C5 root -> referral pain in shoulder

Question 2

Q 2. Cavernous sinus houses which nerves (6)? What are symptoms associated with each nerve?

Answer 2

• post ganglionic sympathetic nerve chain -> Horner
• CN 3-> opthalmolegia
• CN 4-> opthalmoplegia
• CN 5-V1 -> decreased corneal sensation
• CN 5- V2 -> decreased maxillary sensation
• CN 6 -> opthalmoplegia

Foramen Rotundum & Foramen ovale + sympathetic

Question 3

Describe how sympathetic nerve in face runs

: origin, first synapse, second synapse, targets

Answer 3

Hypothalamus

• > first synapse at spinal cord T1 lateral horn
• > run through sympathetic chain , second synapse at superior cervical ganglion
• > run along through internal carotid, cavernous sinus -> sweat gland/ eyelids

Question 4

Q 4. patient with TB, treated with drug, and develops anemia. What is going on?

Answer 4

INH -> B6 depletion -> impaired ALA synthase -> sideroblastic anemia

Question 5

Heme synthesis: discuss all steps that need vitamins as a cofactor

Answer 5

• Methylmalonic-coA -> succinyl-coA : B12

- SuccinylcoA- > ALA : B6

Question 6

Lead poisoning impairs which 2 enzymes in heme synthesis?

Answer 6

ALAD

Ferrochelatase

Question 7

Q 5. cellulitis -> antibIotic tx -> severely hypotensive, diffuse erythematous skin rash: what is going on?

Answer 7

drug induced anaphylaxis

Question 8

Q 5. Name four compounds that mast cell release after its granulation?
Which one is relatively specific to mast cell so that its level can be used to confirm mast cell mediated anaphylaxis?

Answer 8

• tryptase
• heparin
• histamine
• leukotrienes

elevated tryptase can be used as a confirmation for anaphlyaxis

Question 9

Q 5. What is 5-hydroxyindoleacetic acid? In what disease it can be elevated?

Answer 9

5-HIAA, breakdown product of serotonin

carcinoid

Question 10

Q 5. In what disease can calcitonin elevated?

Answer 10

medullary thyroid cancer

Question 11

Q 5. In what circumstance can myeloperoxidase elevated?

Answer 11

MPO is in neutrophil (this enzyme is used during respiratory burst). Thus infection or inflammation

Question 12

Q 6. Describe how degranulation of mast cell occurs

Answer 12

antigen bound IgE attached on mast cell surface

-> antigen-IgE AGGREGATES, grouped together and cross-links

Question 13

Q 7. Naloxone has antagonistic effect on which opioid receptor?

Answer 13

u (mu),

this receptor is the target for majority of opioid

Question 14

Q 7. Describe effect of opioid binding in each receptor

• u
• k
• delta:

Answer 14

• u (mu): CNS, respiratory depression, constipation
• k (kappa): miosis
• d (delta): anti-depressent effect

Question 15

Q 8. Three stop codon sequences?

Answer 15

우아, 우악, 우가

UAA, UAC, UGA

Question 16

Q 8. What is nature of mutation in Duchenne? Which gene? What kind of mutation? What about Becker?

Answer 16

• Duchenne: frameshift or nonsense mutation on dystrophin -> truncated
• Becker: non-frameshifting insertion on dystrophin -> partial function impairment

Question 17

Q 8. non-sense mutation vs. missense mutation

Answer 17

• non-sense: STOP codon

- missense: different amino acid

Question 18

Q 11. What is narcolepsy? What is molecular marker for narcolepsy? how its level changed in CSF analysis? where is it produced?

Answer 18

• excessive drowsiness during day, suddenly falling into sleep
• Hypocretin-1
• lateral hypothalamus

Question 19

Q 11. What molecular marker can be used for diagnosis of Creutzfeldt-Jakob disease?

Answer 19

14-3-3 protein in CSF

Question 20

Q 14. Function of ANP (atrial natriuretic peptide) in

• renal vasculature
• systemic vasculature
• adrenal gland

Answer 20

• renal vasculature: afferent arteriole dilation-> increase GFR
• systemic vasculature: vasodilation
• adrenal gland: inhibit aldo synthesis

Question 21

Q 15. Where is enteropeptidase located? what is its function?

Answer 21

• intestinal brush border

convert chymotrypsin -> trypsin
Trypsin then cuts other zymogens

Question 22

Q 16. Eye opening vs. Eye closing

• which muscle?
• what cranial nerve?

Answer 22

• eye opening
  : CN3, levator palpebrae

-eye closing
: CN7, orbicularis oculi

Question 23

Q 16. Inward deviation of eye is due to defect in what cranial nerve?

Answer 23

CN6 (abducens)

lateral rectus is impaired

Question 24

Q 16. List four phenotypes of CN3 palsy. mechanism of each abnormality?

Answer 24

• ptosis (eye drooping): levator palpebrae
• down-out eye: ocular muscles except SO, LR
• impaired accomodation: parasympathetic- ciliary muscle
• mydriasis: parasympathetic- sphincter

Question 25

Q 17. Describe failure in what embryological stage leads to cleft lip

Answer 25

failure of fusion of medial nasal process (which will become intermaxillary segment) with maxillary process

Question 26

Q 18. What is foam cells in development of artherosclerosis? What is gross appearance?

Answer 26

lipid laiden macrophages | raised yellow spots within artery wall

Question 27

Q 20. What is the most common case for sudden cardiac death from MI?

Answer 27

V fib

Question 28

Q 21. Anatomy: which arteries supply ureter - proximal ureter (1) - distal ureter (3)

Answer 28

- proximal: renal artery | - distal: external iliac, internal iliac, vescial artery

Question 29

Q 22. Which bacteria synthesizes dextrans from sucrose? How is this related to pathogenesis?

Answer 29

Strep virdians Dextrans attach to fibrin-platelet aggregate, housing on valve and cause valvular disease

Question 30

Q 23. Antifungal agents: azoles vs. echinocandins - target? - location of target?

Answer 30

azole: cell membrane (ergosterol) echinocandins: cell wall (polysacchiride)

Question 31

Q 24. What amyloid deposits in myocardium, causing infiltrative restrictive cardiomyopathy?

Answer 31

transthyretin

Question 32

Q 27. Restless leg syndrome - presentations - medication for tx

Answer 32

- abnormal sensation of legs (may be hard to describe), urge to move legs (especially during sleep) & rapid relief with movement - dopamine agonist

Question 33

Q 31. Cryoprecipitate vs. Frozen Fresh Plasma (FFP) - contents - indications

Answer 33

- cryoprecipitate : only cold soluble factors (factor 8, factor 13, fibrinogen, vWF) => coagulation factor deficiencies involving factor 8 & 13 - FFP : all coagulation factors => rapid reversal of warfarin, DIC

Question 34

Q 32. What 3 biosynthesis can NADPH be used?

Answer 34

- fatty acid synthesis - cholesterol - steroid

Question 35

Q 34. What is Reid index? (how do you calculate it?) It can be used for diagnosis of what disease?

Answer 35

- thickness gland mucosal layer/ thickness between epithelium & cartilage (cartilage NOT involved) - Reid index higher than 50% is diagnostic criteria for chronic bronchitis

Question 36

Q 36. Dihydroegortamine - indication - side effect

Answer 36

- acute miagraine | - vasospasm -> prinzmetal (variable) angina

Question 37

Q 37. What are two good diagnostic tools for vertebral osteomyelitis?

Answer 37

- MRI | - blood culrture

Question 38

Q 37. serum protein electrophoresis is diagnostic tool for what disease?

Answer 38

gammaglobulin pathy- ex: multiple myeloma

Question 39

Q 37. CT myelogram - diagnostic tool for what disease? - indcation

Answer 39

- also vertebral pathology ( vertebral osteomyelitis, spine stenosis) - more invasive than MRI, usually reserved for pts who can not do MRI (pacemaker, metallic implant)

Question 40

Q 38. What can exacerbate Wernike encephalopahty? why?

Answer 40

glucose infusion excess glucose will deplete B1, which is required in glycolysis/ TCA as TPP

Question 41

Q 39. What two prior infections predispose to PID (Pelvic Inflammatory disease?

Answer 41

- chlamydia | - N. gonorrhea