3/11 UWORLD -test # 36

Question 1

Q 2. What are two most important metabolites that mediate blood flow autoregulation? explain physiology

Answer 1

NO & adenosine

increasing blood pressure -> stretch vessel -> vasodilation by NO/ adenosine to maintain same blood flow.
If vessel doesn’t stretch, blood flow will increase.

Question 2

Q 14. Autopsy findings (2) of erythroblastosis fetalis?

Answer 2

• multinucleated RBC (immature RBC synthesis/release due to massive RBC destruction)
• extramedullary hematopoiesis (hepatosplenomegaly)

Question 3

Q 16. Anatomy: compare limited ROM in injury of deltoid vs. injury of trapezius. (hint: what nerve innervates each?)

Answer 3

• injury of deltoid: innervated by axillary nerve (C5-T1), impaired abduction of arm BELOW horizontal line
  ( C5-T1 is located BELOW compared to spinal accessory nerve)
• injury of trapezius: innervated by spinal accessory nerve, impaired abduction of arm ABOVE horizontal line
  ( spinal accessory nerve passes through posterior triangle of neck, above C5-T1, thus ABOVE horizontal line)

Question 4

Q 1. Kid with no vaccination, fever, stridor, epiglottis. What infection is this?

Answer 4

H. influenzae

buzzing word: epiglottis and unvaccination

Question 5

Q 1. What is virulence factor of H.Influenzae?

Answer 5

encapsulated bacteria
PRP (Polyribosylribitol phosphate)
PRP capsule protects bacteria from phagocytosis

Question 6

Q 3. What is Pygmalion effect?

Answer 6

practitioner who believes in efficacy of treatment is biased

Question 7

Q 3. What is Hawthorne effect?

Answer 7

study subjects change their behavior as a result of their awareness that they are being studied

Question 8

Q 3. What is Berkson’s bias?

Answer 8

choosing hospitalized patients as control group is biased, they are less healthy

Question 9

Q 7. What are three phenotypes of VIPoma?

Answer 9

• Watery Diarrhea
• Hypokalemia
• Achlorhydria: low gastric acid

VIPoma is also called as WHDA syndrome

Question 10

Q 7. What does cholecystokinin does in terms of gastric emptying?

Answer 10

inhibits gastric emptying to allow more time for gastric digestion

CCK is sort of digestation facillitator

Question 11

Q 8. Mullerian duct

• derivative of what type of nephric duct?
• gives rise to what structure (3)?
• Mullerian duct aplasia phenotype?

Answer 11

• paramesonephric duct
• fallopian tubes, uterus, upper 1/3 vagina
• note: gonad (ovary) is NOT derived from it. Gonad is derived from mesothelial layer of peritoneum
• rudimentary uterus, primary amonorrhea (no uterus!), short vagina.
• note: ovary is intact. Thus normal sexual characteristic developments

Question 12

Q 8. Wolffian duct

• derivative of what type of nephric duct?
• gives rise to what structure (4)?

Answer 12

• mesonephric duct

- SEED
Seminal vesicle
Epididymis
Ejaculatory duct
Ductus deferan
* note: gonad (testis) is NOT derived from it. Gonad is derived from mesothelial layer of peritoneum

Question 13

Q 8. Kallman syndrome

• what embryological abnormality?
• phenotypes (2)

Answer 13

• impaired migration of GnRH cells in hypothalamus & formation of olfactory bulb
• anosmia (impaired smell sensation)
• low GnRH: no secondary sexual development, infertility

Question 14

Q 8. What is phenotype of 47XXX?

Answer 14

• tall stature
• normal sexual development
• slightly low IQ

Question 15

Q 9. ethics: what is the best way to deal with patients who have low level of literacy?

Answer 15

use alternative resources (video, etc) to convey knowledge. Give a written paper will not work

Question 16

Q 10. Is senile endocardial amyloidosis associated with valvular calcification? What pathology may amyloidosis cause?

Answer 16

• no association with calcification

- restrictive cardiomyopathy/ HF

Question 17

Q 10. Dystrophic calcification

• what process is usually preceded?
• histologic finding?
• serum calcium level?

Answer 17

• cell necrosis or injury happens first, then calcification
  : dystropic calcification is secondary to injury or necrosis
• psomma bodies
• normal serum calcium level (vs. metastatic calcification, which occurs in hypercalcemia)

Question 18

Q 10. How does metastatic calcification differ from dystrophic calcification?

Answer 18

metastatic calcification is secondary to hypercalcemia. It happens on normal tissue

Question 19

Q 12. What two cardiac pathology are associated with SLE?

Answer 19

• Libman-Sacks endocarditis (thrombi both sides)

- pericarditis (serositis)

Question 20

Q 13. What is intestinal phase of gastric acid secretion? what mediator is involved? what is mechanism?

Answer 20

• down-regulation of acid secretion as food enters duodenum

- ileum & colon release peptide YY, which inhibits histamine release from ECL cells

Question 21

Q 13. What is cephalic phase of gastric acid secretion?

Answer 21

acid secretion by cholinergic and vagal stimulation

stimulated by smell, visual, taste of food

Question 22

Q 13. What is gastric phase of gastric acid secretion?

Answer 22

acid secretion by gastrin

Question 23

Q 15. Damage to what nerve causes deltoid flattening? what injury is commonly associated with it?

Answer 23

axillary nerve damage

anterior dislocation of humerus (remember axillary nerve runs posteriorly and comes back anteriorly around humeral head)

Question 24

Q 17. Describe lung abscess in chest X-ray

Answer 24

cavitary lesion with air-fluid levels

Question 25

Q 17. Describe chest x-ray of TB

Answer 25

cavitary lesion, but NOT air-fluid levels

Question 26

Q 17. symptoms (5) of lung abscess?

Answer 26

- copious production of foul smelling sputum (also green color) - fever - malaise - weight loss - cyanosis

Question 27

Q 17. Compare pathophysiology: pneumonia vs. penumonitis

Answer 27

pneumonia: aspiration of bacteria pneumonitis: aspiration of gastric acid

Question 28

Q 18. phosphoribosyl pyrophosphate amidotransferase facilitates what rxn? - what metabolites regulate its function? - What disease causes increased level of PRPP amidotransferase?

Answer 28

- synthesis of IMP - IMP, AMP, GMP down-regulates PRPP amidotransferase level: this makes sense because these are end products of purine salvage pathway - Lesch-Nyhan syndrome: lack HGPRT -> less GMP/AMP - > increased PRPP amidotransferase

Question 29

Q 18. 5 symptoms of Lesch-Nyhan syndrome?

Answer 29

``` H- Hyperuricemia G- Gout P- Pissed off (self-mutilation, agitated) R- mental Retardation T- dysTonia ```

Question 30

Q 19. Cefuroxime is what class of drug?

Answer 30

2nd generation cephalosporin - sketchy: FURious second guy. ceFURoxime

Question 31

Q 19. Chloramphenicol - MOA - indications (2) - side effects

Answer 31

- ribosome 50S subunit inhibitor - meningitis, rocky mountain spotted fever : not commonly used in U.S. but used in developing countries due to low cost - grey baby syndrome (hypothermia, flaccidity), aplastic anemia

Question 32

Q 20. What is the most common complication of shingles?

Answer 32

Post Herpetic Neuralgia (PHN) | : pain persists for several months even after rash (dermatome distribution) is gone

Question 33

Q 22. What are two major characteristics of menigioma

Answer 33

- cells arranged in whorled pattern (spiral wave) | - psammoma bodies

Question 34

Q 24. Subarachnoid hemorrhage - most common pathophysiology? - most common complication? - method to detect complication? - medication to prevention?

Answer 34

- saccular aneurysm - vasospasm (vessels surrounding ruptured artery) - CT will not catch vasospasm, transcranial color doppler is required - nimodipine (dihydropyridine CCB)

Question 35

Q 25. Tamoxifen vs. Raloxifene - indications - side effects

Answer 35

Tamoxifen - indication: breast cancer - side effects: DVT/PE, hot flashes, endometrial cancer Raloxifene - indication: postmenopausal osteoporosis - side effects: DVT/PE

Question 36

Q 26. What is Dandy-Walker malformation?

Answer 36

- CYSTIC dilation of FOURTH ventricle - absence/hypoplasia of cerebellar vermis non-communicating hydrocephalus

Question 37

Q 28. Erythropoietin as medication - indication - side effects (2)

Answer 37

- anemia ( in CKD) - thrombosis (hyperviscosity) - hypertension (stimulation of EPO receptor in endothelium: exact mechanism unknown)

Question 38

Q 30. Which drug is indicated for anaphylaxis (or anaphylactic shock)?

Answer 38

epinephrine non-specific alpha/beta agonist alpha- vasoconstriction beta- cardiac output increase -> reduce hypotension

Question 39

Q 30. What norephinephrine is not indicated for anaphylaxis?

Answer 39

compared to epinephrine, NE is alpha1 specific. It can reduce vasodilation effect of anaphylaxis, but may not ultimately enhance hypotension due to limited cardiac output (increased afterload)

Question 40

Q 33. What is key requirement for diagnosis of tetanus?

Answer 40

history and physical examination * bacterial toxin assay/ antibody test are not available * blood culture is not feasible due to poor bacterial growth on culture. It is toxin that causes disease

Question 41

Q 35. Hospital action for reduction of MRSA vs. MSSA (methicillin sensitive Staph. aureus)?

Answer 41

MRSA- contact precaution required MSSA- contact precaution is not required. Hand hygiene is enough

Question 42

Q 38. What lung cancer is associated with ectopic ACTH (thus cushing)?

Answer 42

small cell lung cancer

Question 43

Q 39. In hypovolemic state, describe level change/ physiology of - RPF - GFR - FF

Answer 43

low blood pressure - > renal blood flow is limited - > decrease in GFR -> increase in AngII - > maintenance of GFR (but GFR is still reduced due to severe reduction in renal blood flow) - > increase in FF (GFR decrease is less significant compared to RPF)

Question 44

Q 37. Which two rxns of phenylalanine metabolism require tetrahydrobiopterin as a cofactor?

Answer 44

- phenylalanine -> tyrosine (phenylalanine hydroxylase) - tyrosine -> DOPA (tyrosine hydroxylase) These two rxns need BH4: hydroxylation

Question 45

Q 37. Deficiency of which enzyme results in reduction of BH4? what are three phenotypes?

Answer 45

- Dihydrobiopterin reductase (BH2 -> BH4) | - hyperphenylalaniema, hyperprolactinemia (less dopamine), hypotonia (less muscular stimulation by NE, epinephrine)