4

Question 1

A type 2 diabetic with a HgbA1c of 10% presents to your clinic with many complaints. You are concerned about the effect of the patient’s long-term hyperglycemia. What diabetic complications can be attributed to sorbitol-induced osmotic damage? Which enzyme converts glucose to sorbitol? (FA15 p104) (FA16 p92)

Answer 1

aldose reductase converts glucose–>sorbitol
sorbitol dehydrogenase converts sorbitol to fructose

lack of sorbitol dehydrogenase–>buildup:
osmotic damage: cataracts, retinopathy, and peripheral neuropathy (damage to Schwann cells) seen with chronic hyperglycemia in diabetes

2 mechs of destruction in DM:
glycosylation of BVs
sorbitol induced osmotic damage

Question 2

Which efferent fibers carry input from the brain that influences the outer hair cells (OHCs) of the cochlea in much the same way that gamma motor neurons influence muscle spindles? What is the result of this input? What is the result of damaging the OHCs (as with antibiotics such as gentamicin and streptomycin)?

Answer 2

olivocochlear bundles: contraction of outer hair cells–>stiffing of basilar membrane in cochlea–>sensitizes inner hair cells to particular frequency

damage of OHCs results in wide deflection of basilar membrane (vs. sharp)–>hearing loss

Question 3

What is type II (β) error? (FA15 p54) (FA16 p38)

Answer 3

not finding a result that is actually there

Stating that there is not an effect or difference when one exists (null hypothesis is not rejected when it is in fact false)

Question 4

A child in India is brought to the doctor with symptoms of muscle weakness, malaise, headache, fever, and hyporeflexia. For the past few weeks, he had been swimming in a waterway known to contain sewage. You think this boy has contracted a pathogen via the fecal-oral route. Which area of the body is this pathogen attacking to give the neurologic symptoms seen? (FA15 p471) (FA16 p474)

Answer 4

polio virus: destruction of cells in anterior horn of SC–>LMN signs

Question 5

What are the risk factors for osteosarcoma? (FA15 p428) (FA16 p429)

Answer 5

Paget disease of bone, bone infarcts, radiation, familial retinoblastoma, Li-Fraumeni syndrome (germline p53 mutation), male sex, age 10-20 yrs

(2nd most common 1o malignant bone tumor after multiple myeloma)

Question 6

What disorders can cause cotton-wool spots on the retina?

Answer 6

pale areas, infarcts of nerve fiber layer of retina

causes: chronic HTN, DM retinopathy, AIDS, Lutus, Temporal giant cell arteritis, Wegener’s, polyarteritis nodosa

Question 7

Which cardiac valve is most commonly involved in infective endocarditis and acute rheumatic fever?
(FA15 p298-299) (FA16 p293-294)

Answer 7

Mitral
(M>A>T)

Tricuspid in IVDU (venous return)

Question 8

Name the syndromes below that are common causes of anovulation. (FA15 p323, 585) (FA16 p317, 591)
elevated cortisol, central obesity 
amenorrhea + hirsutism + obesity

Answer 8

elevated cortisol, central obesity: Cushing’s syndrome
amenorrhea + hirsutism + obesity: PCOS: Polycystic ovarian syndrome (Stein- Leventhal syndrome)

PCOS: Hyperinsulinemia and/or insulin resistance hypothesized to alter hypothalamic hormonal feedback response–>^^􏰄􏰂LH:FSH ^􏰂androgens from theca interna cells, dec. 􏰅rate of follicular maturation–>􏰄unruptured follicles (cysts) + anovulation

Question 9

Which neurotransmitters in the brain are affected in each of the following disorders? Are the levels increased or decreased? (FA15 p507) (FA16 p511)
Schizophrenia
Parkinson disease
Alzheimer disease Huntington disease
Anxiety
Depression

Answer 9

Schizophrenia: ^^dopamine
Parkinson disease: decreased dopamine, ^^ACh, ^^serotonin
Alzheimer disease: dec. ACh, ^^glutamate
Huntington disease: dec. GABA, dec. ACh, ^^dopamine,
Anxiety: ^^NE, dec. serotonin, dec. GABA
Depression: dec. NE, dec. dopamine, decreased serotonin

Huntington's and Parkinsons are close to opposites 
tx schizo (trying to dec. dopamine)  can induce parkinsonism: opposite dopamine fluctuations

Question 10

What is the underlying cause of DiGeorge syndrome? What are the manifestations of DiGeorge syndrome? (FA15 p88, 214, 566) (FA16 p76, 208, 570)

Answer 10

thymic aplasia: 22q11 deletion; failure to develop 3rd and 4th pharyngeal pouches–>􏰄absent thymus and parathyroids.
hypoPTH, hypocalcemia (tetany), recurrent viral/fungal infections (T-cell deficiency), conotruncal abnormalities (e.g., tetralogy of Fallot, truncus arteriosus)
absent thymic shadow on CXR
may see cleft palate, abnormal facial features

Question 11

Which immune response is responsible for hyperacute, acute, and chronic transplant rejection? What is the time frame for each? (FA15 p217) (FA16 p211)

Answer 11

hyperacute (w.in minutes): Pre-existing recipient antibodies react to
donor antigen (type II HSR), activate complement
acute (weeks-mos): Cellular: CD8+ T cells activated against donor MHCs. Humoral: similar to hyperacute, except antibodies develop after transplant.
chronic (mos-yrs): CD4+ T cells respond to recipient APCs presenting donor peptides, including allogeneic MHC.
Both CMI and Hum.

Question 12

What is the treatment for digoxin toxicity? (FA15 p257) (FA16 p251)

Answer 12

digoxin immune Fab fragments

Question 13

For which infections is vancomycin a good choice? How does vancomycin resistance develop? (FA15 p183) (FA16 p173)

Answer 13

G+, serious MDR: MRSA, S. epidermidis, ensitive Enteroccocus species, and C. diff (oral dose for pseudomembranous colitis)
resistance: amino acid modification of D-ala D-ala to D-ala D-lac.
“Pay back 2 D-alas (dollars) for vandalizing (vancomycin).”

Question 14

Do atypical antipsychotics primarily address the negative or positive symptoms of schizophrenia? How does the mechanism of action of typical antipsychotics differ from the mechanism of action of the atypical antipsychotics? (FA15 p509, 521) (FA16 p514, 525)

Answer 14

Schizophrenia—both positive and negative symptoms
atypical MOA: Not completely understood. Varied effects on 5-HT2, dopamine, and α- and H1-receptors
All typical antipsychotics block dopamine D2 receptors (^^􏰂[cAMP]).

atypicals: Olanzapine, clozapine, quetiapine, risperidone, aripiprazole, ziprasidone.

“It’s atypical for OLd CLOZets to QUEITly RISPER from A to Z.”

Question 15

A 67-year-old man with new-onset hepatic failure and normal renal function is currently taking a drug metabolized and excreted by the kidneys. Would you need to change the loading dose or maintenance dose of this medication because of this hepatic failure? If this patient were to develop hepatorenal failure, would you need to change the loading dose or maintenance dose of the medicine? (FA15 p243) (FA16 p237)

Answer 15

decrease the maintenance dose, not loading dose if hepatorenal failure, not nec. to adult in hepatic failure

Question 16

What substances compose the matrix of the bone?

Answer 16

70% crystalline salts: Ca2+, phos, hydrapatite, conjugated ions, Na+, Mg++
30% organic: collagen, chondroitin sulf. hyaluronic acid

Question 17

While thiazide and loop diuretics are known for wasting potassium in the urine, there are other diuretics that conserve it. Which diuretics are these? What are their mechanisms of action? What are their important side effects? (FA15 p554) (FA16 p558)

Answer 17

aldosterone antagonists: spironolactone, epleronone
Na+ channel blockers: triamterene, amiloride
-both work at cortical collecting tubule
SEs: Hyperkalemia (can lead to arrhythmias), endocrine effects with spironolactone (e.g., gynecomastia, antiandrogen effects).

Question 18

A 66-year-old woman is being treated in the ER for an acute MI. Nitroglycerin is given with the expectation that it will vasodilate which vessels preferentially? Another patient in the ICU is on hydralazine for acute treatment of his severe hypertension. How does hydralazine function? (FA15 p304-305) (FA16 p298-299)

Answer 18

venodilators (dec. preload)

hydralazine dilates arteries (dec. afterload)

Question 19

What risk factors are associated with cholesterol gallstones? What risk factors are associated with pigment gallstones? (FA15 p375) (FA16 p372)

Answer 19

cholesterol stone risk factors: obesity, Crohn disease, advanced age, clofibrate, estrogen therapy, multiparity, rapid weight loss, Native American origin
pigment stones risk factors: seen in patients with chronic hemolysis, alcoholic cirrhosis, advanced age, biliary infections, total parenteral nutrition (TPN)

Question 20

A 35-year-old woman with multiple sclerosis presents to clinic with internuclear ophthalmoplegia. What is internuclear ophthalmoplegia? (FA15 p486) (FA16 p490)

Answer 20

Lesion in MLF, a conjugate horizontal gaze palsy. Lack of communication such that when CN VI nucleus activates ipsilateral lateral rectus, contralateral CN III nucleus does not stimulate medial rectus to fire. Abducting eye gets nystagmus (CN VI overfires to stimulate CN III). Convergence normal
MLF in MS

Question 21

A female infant is brought to the clinic for evaluation of her genitalia. On exam, clitoromegaly and labial fusion is noted. Lab studies reveal elevated 17-hydroxyprogesterone levels. What is the most common form of adrenal hyperplasia? Which hormone levels are altered as a result of this enzyme deficiency? What are the clinical manifestations of this enzyme deficiency? (FA15 p318) (FA16 p312)

Answer 21

21-hydoxylase deficiency
increase 17-hydroxyprogesterone, increase androgens, decrease mineralcorticoids
21: dec. BP, inc. sex hormones

IN CONTRAST:
11 (B-hydroxylase): increase in BP and androgens ^^
17 (a-hydroxylase): increase in BP, decrease in sex hormones

Question 22

What is the mechanism of action of the following antiemetics? (FA15 p251, 380) (FA16 p245, 376)
Scopolamine
Promethazine
Prochlorperazine
Metoclopramide
Ondansetron

Answer 22

Scopolamine: musc. antag. @ CNS
Promethazine and Prochlorperazine: dopamine (D2) receptor antagonists that belongs to the phenothiazine class
Metoclopramide: D2 receptor antagonist. ^^􏰂resting tone, contractility, LES tone, motility. Does not influence colon transport time.
Ondansetron: 5-HT3 antagonist; dec. 􏰅vagal stimulation. Powerful central-acting antiemetic

Question 23

A 25-year-old man complains of a scrotal mass and pain made worse by coughing or sneezing. A scrotal exam reveals a palpable scrotal protrusion with the Valsalva maneuver. What type of hernia is this patient experiencing? What type of hernia protrudes through Hesselbach’s triangle? What structures form Hesselbach’s triangle? (FA15 p352) (FA16 p349)

Answer 23

Can’t tell via exam

Direct: Protrudes through the inguinal (Hesselbach) triangle. Bulges directly through abdominal wall medial to inferior epigastric artery. Goes through the external (superficial) inguinal ring only. Covered by external spermatic fascia. Usually in older men.

Indirect: Goes through the internal (deep) inguinal ring, external (superficial) inguinal ring, and into the scrotum. Enters internal inguinal ring lateral to inferior epigastric artery. Occurs in infants owing to failure of processus vaginalis to close (can form hydrocele). Much more common in males. covered by all 3 layers of spermatic fascia
“MDs don’t LIe”:
Medial to inferior epigastric artery = Direct hernia.
Lateral to inferior epigastric artery = Indirect hernia
Hesselbach triangle:􏰃 Inferior epigastric vessels,􏰃 Lateral border of rectus abdominis,􏰃 Inguinal ligament

Question 24

How does a decrease in renal artery pressure cause an increase in blood pressure? (FA15 p534) (FA16 p540)

Answer 24

increase in renin to compensate, increase Ang II–>vasoconstriction and increase aldosterone

Question 25

What are the three endogenous androgens in order from the most potent to the least potent? (FA15 p577) (FA16 p582)

Answer 25

DHT>Testosterone>androstenedione

Question 26

What is Osler-Weber-Rendu syndrome? (FA15 p83) (FA16 p71)

Answer 26

Hereditary hemorrhagic telangiectasia: Inherited disorder of blood vessels. Findings: branching skin lesions (telangiectasias), recurrent epistaxis, skin discolorations, arteriovenous malformations (AVMs), GI bleeding, hematuria

Question 27

What is the fibrous band attached to the testis and scrotum that aids in normal testicular descent? What is this structure called in females? (FA15 p569) (FA16 p573)

Answer 27

Gubernaculum

Ovarian ligament + round ligament of uterus.

Question 28

What are the effects of NSAIDs’ inhibition of PGE2? (FA15 p445) (FA16 p447)
What role do prostaglandins and angiotensin II play on the renal arterioles? (FA15 p530, 532) (FA16 p535, 537)

Answer 28

Block PGE2 synthesis
PGs vasodilate afferent arteriole,
AngII constricts efferent arteriole,
both increase GFR

Question 29

What is the difference between a case-control study, a cohort study, and a clinical trial? (FA15 p48) (FA16 p32) (SU p17-18)
Which studies use odds ratios, and which use relative risks? (FA15 p48, 50) (FA16 p32, 34) (SU p18)

Answer 29

Case-control: retrospective; Compares a group of people with disease to a group without disease. Looks for prior exposure or risk factor. Asks, “What happened?” (odds ratio)
Cohort: Prospective or retrospective Compares a group with a given exposure or risk factor to a group without such exposure. Looks to see if exposure ^^ 􏰂the likelihood of asks, “Who will/has develop(ed) disease?” (relative risk)
clinical trial: Compares therapeutic benefits of 2 or more treatments, or of treatment and placebo

Question 30

T cells are found in the paracortex of the lymph node between the follicles and the medulla. Which cytokines are secreted by the two different types of helper T cells (Th1 and Th2)? (FA15 p202) (FA16 p194)

Answer 30

Th1: secretes IFN-γ, Activates macrophages and cytotoxic T cells, Activated by INF-γ and IL-12 (released by macrophages), Inhibited by IL-4 and IL-10 (from Th2 cell)

Th2: secretes IL-4, IL-5, IL-10, IL-13, Recruits eosinophils for parasite defense and promotes IgE production by B cells, Activated by IL-4, Inhibited by IFN-γ (from Th1 cell)

Question 31

A 32-year-old man is being treated for alcohol dependence with disulfiram. One night, he begins drinking and later has severe nausea and vomiting. What is the mechanism of action of disulfiram? What other drugs have a disulfiram-like effect? (FA15 p95) (FA16 p83)

Answer 31

inhibits acetaldehyde dehydrogenase (acetaldehyde accumulates, contributing to hangover symptoms)
certain cephalosporins, metronidazole, griseofulvin, procarbazine, 1st-generation sulfonylureas

Question 32

What is PPAR-γ? How is it relevant to the treatment of diabetes mellitus? (FA15 p338-339) (FA16 p334-335)

Answer 32

Genes activated by PPAR-γ (Peroxisome proliferator-activated receptor gamma) regulate fatty acid storage and glucose metabolism. Activation of PPAR-γ􏰂insulin sensitivity and levels of adiponectin.

Glitazones/ thiazolidinediones: Pioglitazone, Rosiglitazone (for T2 DM) increase insulin sensitivity in peripheral tiss. by binding to PPAR-y nuclear transcription regulator

Question 33

The thalamus is a relay station that conducts signals to and from the brain. Which thalamic nuclei are the relay stations for each of the following body sensations/activities? (FA15 p456) (FA16 p458)
VPL
VPM
LGN
MGN
VL

Answer 33

VPL: Pain, temperature; pressure, touch, vibration, proprioception (STT, DCML–>1o SMS cortex)
VPM: Face sensation (“Makeup on the Face), taste (trig./gust–>1o SMS cortex)
LGN: vision (Lateral=Light) (CNII–>calcarine sulcus)
MGN: hearing (Medial=Music) (sup. olive, inf. colliculus of tectum–>aud. cortex of temp. lobe)
VL: motor (basal gang., CBLLM–>motor cortex)

Question 34

A 40-year-old man arrives at your clinic for his first physical in 20 years. He reeks of cigarette smoke, and you notice his jacket bears the logo of his favorite tobacco company. He proudly informs you that he got this great jacket by redeeming his cigarette cartons. At what stage of change in overcoming his smoking habit is this man? (FA15 p517) (FA16 p521)

Answer 34

pre-contemplation

next steps: 
contemplation
preparation/determination
action/willpower
maintenance
relapse

Question 35

A 23-year-old man comes to your clinic with a fever of 39°C, a headache, and myalgias. This is the second fever he has had in the last two weeks. He recently finished treatment to eradicate the lice infestation that he acquired during a recent trip to Mexico. What organism might be responsible for this man’s recurrent fever? (FA15 p142) (FA16 p132)

Answer 35

Borrelia recurrentis

Question 36

What physiologically is taking place in decompression sickness?

Answer 36

dissolved gases (N2) coming out of solution into bubbles inside the body on depressurisation

Question 37

Which drugs are known to cause aplastic anemia? What is the treatment for aplastic anemia? (FA15 p258, 393) (FA16 p252, 391)

Answer 37

Carbamazepine, Methimazole, NSAIDs, Benzene, Chloramphenicol, Propylthiouracil
“Can’t Make New Blood Cells Properly”
(Caused by failure/destruction of myeloid stem cells)–>pancytopenia
tx: w/draw offending agent, immunosuppressive regimens (e.g., antithymocyte globulin, cyclosporine), BM allograft, RBC/platelet transfusion, BM stimulation (e.g., GM-CSF).

Question 38

Is a 34-year-old schizophrenic patient having active hallucinations, who is not oriented to time, place, or person, able to legally agree to a plan of care? What factors must be in place in order for a patient to have the capacity to make a decision? (FA15 p57) (FA16 p40)

Answer 38

NO, patient requirements:
≥ 18 years old or otherwise legally emancipated
-makes and communicates a choice
-is informed (knows and understands)
-Decision remains stable over time, is consistent with patient’s values and goals, not clouded by a mood disorder, and is not a result of AMS (delusions, delirium, hallucinations)

Question 39

A 34-year-old woman develops a painful right eye with decreased visual acuity. Exam demonstrates a firm right eye. What type of glaucoma is the patient experiencing? What is the difference between the mechanism of closed- and open-angle glaucoma? What is the fundoscopic finding associated with glaucoma? (FA15 p480, 494) (FA16 p484, 498)

Answer 39

acute closed-angle: (primary) enlargement or forward movement of lens against central iris (pupil margin)–>􏰄obstruction of normal aqueous flow through pupil–>􏰄fluid builds up behind iris, pushing peripheral iris against cornea and impeding flow through trabecular meshwork (secondary from hypoxia–> vasoproliferation in iris that contracts angle)

open-angle (secondary): blocked trabecular meshwork from WBCs (e.g., uveitis), RBCs (e.g., vitreous
hemorrhage), retinal elements (e.g., retinal detachment).

INCREASED cup:disc ratio (0.3–>0.8), elevated IOP, peripheral visual field loss

Question 40

A 1-year-old boy is brought to the clinic for evaluation of his skin. The patient’s skin was normal at birth but now is erythematous, scaly, and has many new freckles. Workup and an astute attending reveal that this child has xeroderma pigmentosum. What cancers will this child be at higher risk of developing? (FA15p235)

Answer 40

SqCC, BCC, melanoma

-defective nucleotide excision repair: prevents repair of pyrimidine dimers because of UV light exposure

Question 41

What is the treatment for closed- and open-angle glaucoma?

Answer 41

-α-agonists: Epinephrine (α1) Brimonidine (α2): decrease aqueous humor synthesis (not for closed angle)
-β-blockers: Timolol, betaxolol,
carteolol: decrease aqueous humor synthesis
-diuretics: acetozolamide: dec. aqueous humor synthesis via inhibition of carbonic anhydrase
-Cholinomimetics: Direct (pilocarpine, carbachol)
Indirect (physostigmine, echothiophate) ^^ outflow of aqueous humor via contraction of ciliary muscle and opening of trabecular meshwork
pilocarpine in emergencies

Question 42

What organism causes Hansen disease? What animal serves as the reservoir for this organism in the U.S.? Where in the body does this organism live? (FA15 p134) (FA16 p125)

Answer 42

M. leprae
armadillo
infects skin and superficial nerves—“glove and stocking” loss of sensation

Question 43

What is BNP, and how is it useful in cases of heart failure? (FA15 p285) (FA16 p279)

Answer 43

Released from ventricular myocytes in response to increased 􏰂tension. Similar physiologic action to ANP, with longer half-life. BNP blood test used for diagnosing HF (very good negative predictive value). Available in recombinant form (nesiritide) for treatment of HF

Question 44

A 9-year-old child is brought into the clinic for evaluation of a right wrist drop and confusion. Physical exam reveals a bluish line on the gingivae. What peripheral smear finding is consistent with lead poisoning? What is the treatment for lead poisoning in this patient? (FA15 p388, 391) (FA16 p386, 389)

Answer 44

basophilic stippling
Succimer used for chelation for kids (It “sucks” to be a kid who eats lead).
+/- Dimercaprol

Question 45

A 62-year-old man complains of weak urine stream and hesitancy when trying to urinate. His physician prescribes finasteride. How does this agent treat benign prostatic hyperplasia? (FA15 p597) (FA16 p603) (SU p217, 223)

Answer 45

A 5α-reductase inhibitor (decreases 􏰅conversion of testosterone to DHT)
used for BPH and male-pattern baldness

Question 46

A kidney transplant patient begins to experience renal failure seven years after receiving her kidney transplant. What type of rejection is this, and how is it mediated? (FA15 p217) (FA16 p211)

Answer 46

Chronic rejection: mediated by CD4+ T cells responding to recipient APCs presenting donor peptides, including allogeneic MHC
-both cellular and immune components
-Recipient T cells react
and secrete cytokines–> 􏰄proliferation of vascular smooth muscle and parenchymal fibrosis. Dominated by arteriosclerosis.

Question 47

What test is used to detect corneal abrasions?

Answer 47

Fluorescein dye, examine under microscope

Question 48

What physiology accounts for the automaticity of the AV and SA nodes? (FA15 p281) (FA16 p275)

Answer 48

slow spontaneous diastolic depolarization as Na+ conductance􏰂 increases

Question 49

What is p value? What is an acceptable p value? (FA15 p54) (FA16 p38)

Answer 49

probability that a study’s results occurred by chance alone

p-value less than 0.5 is statistically significant

Question 50

A patient with an epilepsy diagnosis is pregnant with her first child. She is concerned that her child may also have seizures. What are the most common causes of seizures in children? In adults? In the elderly? (FA15 p489) (FA16 p494)

Answer 50

Children—genetic, infection (febrile), trauma, congenital, metabolic
Adults—tumor, trauma, stroke, infection
Elderly—stroke, tumor, trauma, metabolic, infection

Question 51

Which diuretics lower serum calcium levels? What is the mechanism by which these cause hypocalcemia? (FA15 p553-554) (FA16 p557-558)

Answer 51

loop diuretics
Inhibit cotransport system (Na+/K+/2Cl−) of thick ascending limb of loop of Henle. Abolish hypertonicity of medulla, preventing concentration of urine. Stimulate PGE release (vasodilatory effect
on afferent arteriole); inhibited by NSAIDs. increase 􏰂Ca2+ excretion, Ca2+ reabsorbed paracellularly, dependent on gradient generated by Na+/K+/2Cl− pump. Loops Lose Ca2+.