3/13 UWORLD- test # 40

Question 1

Q 1. During myocardial ischemia

• How does ATP change as time goes by? why?
• How does lactate change as time goes by?
• when does loss of muscle contractility occur?
• Beginning at onset of MI, when does it result in irreversible damage?

Answer 1

• ATP drops as time goes by. Because MI induces conversion from aerobic glcolysis to anerobic glycolysis
• lactate builds up as time goes by due to anerobic glycolysis
• loss of muscle contractility occurs 30 seconds (SUPER QUICK) after MI
• 30 mins after MI, damage becomes irrerversible

Question 2

Q 3. Embryological origin of posterior pituitary?

Answer 2

neural tube

Question 3

Q 3. Embryological origin of anterior pituitary?

Answer 3

oral ectoderm (Rathke pouch)

Question 4

Q 3. Embryological origin of pineal gland?

Answer 4

neural tube

Question 5

Q 3. Embryological origin of Schwann cell?

Answer 5

neural crest

Question 6

Q 3. Embryological origin of thymus?

Answer 6

endoderm

Question 7

Q 3. several pigmented spots + multiple subcentimeter, fleshy, cutaneous tumors… Diagnosis?

Answer 7

neurofibroma type 1 (NF1)

• several pigmented spots: cafe-au-lait
• multiple fleshy CUTANEOUS tumors: cuteneous neurofibroma

Question 8

Q 3. Which cell is neurofibroma derived from? embryological origin?

Answer 8

• schawann cells

- nerual crest

Question 9

Q 4. Does Klinefelter syndrome result in intellectual disability?

Answer 9

Yes.

Question 10

Q 4. short stature, obesity, intellectual disability: what genetic disease is this? What genetic abnormality?

Answer 10

Prader- Willi

maternally imprinted gene. 
Thus Paternal (P as Parader Willi ) gene on chromosome 15 is mutated/deleted

Question 11

Q 5. getting sick after eating mushroom what is going on?

Answer 11

death cap mushroom (Amanita phalloides) release toxin that inhibits RNA polymerase II, inhibiting mRNA synthesis

Question 12

Q 9. Conus medullaris syndrome

• lesion at where?
• symptoms? These symptoms are associated with what nerve branch?

Answer 12

• L2

- impaired bladder (urination), impaired defecation (anal sphincter), and impotence: S3-S4 root

Question 13

Pudendal nerve

• what is nerve root?
• what bony landmark is used for injection to numb pudendal nerve during delivery

Answer 13

• S2-S4

- ischial spine is bony landmark for injection to numb pudendal nerve

Question 14

Q 10. Behavioral control for insomnia: example of each?

• sleep hygiene
• stimulus control

Answer 14

• sleep hygiene: avoid alcohol, naps, alcohol..
  : hygiene- make sleep CLEAN
• stimulus control: sleep only when you are sleep
• > leave bed if unable to fall a sleep in 20 mins

Question 15

Q 12. How does synchronization of glycogen breakdown and muscle contraction occurs? what is key mediator for this?

Answer 15

Intracellular Ca2+

• > activates PK (phosphorylase kinase)
• > phosphorylated glycogen phosphorylase becomes active form
• > glycogen breakdown

Question 16

Q 13. What is central scotomata? What does scotomata mean?

Answer 16

• lesion in macula.

- socotomata: lesion in the middle, where peripherally surrounded by normal tissue

Question 17

Q 14. Diarrhea causing infectious bugs that do not need many numbers to cause symptom? (4)

Answer 17

• shigella
• entamoeba
• Giradia
• camplyobacter

Question 18

Q 16. E.coli: what toxin causes meningitis?

Answer 18

K capsule

Question 19

Q 17. What is Cushing triad? what does it suggest?

Answer 19

• HTN, bradycycardia, bradypnea
• increased ICP
• increased ICP -> vessel constriction -> HTN
• > baroreceptor

bradypnea is because respiratory fucked up

Question 20

Q 21. Explain hypercalcemia in sarcoidosis. What cell mediates this?

Answer 20

ACTIVATED MACROPHAGE (by INF-gamma) overproduces 1-alpha hydroxylase -> more 1,25-OH2 vitamin D

Question 21

Q 22. How does erythema multiforme look like? What infections (2) are associated with it?

Answer 21

• target cell

- mycoplasma & HSV

Question 22

Q 22. Apart from infection what three other conditions are associated with erythema multiforme?

Answer 22

• drugs (sulfa drugs, phenytoin)
• cancer
• autoimmune diseases

Question 23

Q 23. Class 1 drugs: Compare binding affinity to Na+ channel

Answer 23

1C> 1A> 1B

sketchy: third floor (1C) TV watching guy tightly holding peanut butter jar.
First floor (1A) queen holding peanut peanut butter loosely, while 2nd floor angry girl does not hold peanut butter at all.

Question 24

Q25. What lipid drug causes gallstone?

Answer 24

gemfibrozil

Question 25

Q 24. Friedreich ataxia

• what nucleotide repeat on what gene/ chromosome
• associations (5)

Answer 25

• GAA repeat in frataxin on chromosome 9

1. diabetes
2. hypertrophic cardiomyopathy
3. gait
4. foot abnormality: hammer toe, pes cavus- high arch
5. nystagmus

Question 26

Q 26. What is triamterene?

Answer 26

K+ sparing ENaC blocker

same as amiloride

Question 27

Q 27. What bad two side effects of Dipenhydramine may present in old people

Answer 27

confusion, hallucination

Question 28

Q 32. Gross appearance during the first 4 hours in acute MI?

Answer 28

normal appearance. No change.

• early coagulative necrosis kicks in after first 4 hours
  neutrophil kick in after 24hrs

Question 29

Q 33. uncontrolled voiding without sensation of full bladder- what type of urinary incontinence?

Answer 29

overflow incontinenece

Question 30

Q 35. What does insulin do for potassium level? why?

Answer 30

hypokalemia

insulin activates Na+/K+-ATPase: more potassium dragged intracellularly

Question 31

Q 35. What is treatment option for DKA? What does this treatment change below, why?

• Na+
• K+
• HCO3-

Answer 31

tx DKA: saline + insulin

• Na+: elevated- rehydration of normal saline
• K+: low- insulin causes hypokalemia
• HCO3-: elevated- less ketone acid production

Question 32

Q 36. What enzyme/rxn are responsible for regeneration of NAD+ in glycolysis?

Answer 32

lactate dehyrogenase

Question 33

Q 37. Ulcer at which spot indicates very low chance of malignancy?

Answer 33

duodenum

vs. gastric or colon: ulcer increases risk for cancer