UWorld High Yield Review Flashcards
presence of which of the following conditions in a patient’s PMH would make celecoxib the preferred NSAID?
a. hyperlipidemia
b. Hypertension.
c. Peptic ulcer disease.
d. Renal impairment.
e. Stable angina
c. Peptic ulcer disease.
selective COX2 inhibitors have a lower risk of bleeding and gastric ulceration than non-selective NSAIDs
describe the effect of ACE inhibitors on renal function
recall that angiotensin II causes systemic vasoconstriction, constriction of the glomerular efferent arteriole (maintaining GFR), and enhanced aldosterone secretion
so, ACEi dilate the efferent arteriole, causing a reduction in GFR and systemic vascular resistance
which of the following drugs inhibits primary active transport?
a. tetrodotoxin.
b. Verapamil.
c. Omeprazole.
d. Lidocaine.
e. Dofetilide.
c. Omeprazole: PPI, suppresses parietal H/K ATPase
a. tetrodotoxin: blocks voltage-gated Na+ channel in nerve cell membranes
b. Verapamil: blocks L-type Ca2+ channels in cardiomyocytes
d. Lidocaine: blocks voltage-gated Na+ channels (class IB)
e. Dofetilide: blocks passive K+ transporter of outward rectifier current in cardiomyocytes (class III)
culture of an intraabdominal abscess would most likely show:
a. Staph. aureus
b. Bacteroides fragilis
c. Entamoeba histolytica
intra-abdominal infections are polymicrobial with Bacteroides fragilis (anaerobe, Gram neg. rod) and E. coli (Gram neg. rod) being the most prominent organisms identified
[S. Aureus common in liver abscess]
rate the strength of Na+ channel binding of the Class I antiarrhythmics and name one example of each
strongest binding = slower disassociation: class 1C (flecainide, propafenone)
Class 1A: quinidine, procainamide, disopyramide
Weakest binding = faster disassociation: class 1B (lidocaine, mexiletine)
EKG shows P waves of varying morphology
wondering atrial pacemaker or ectopic atrial rhythm – ectopic atrial foci replace sinus node as the dominant pacemaker
16-year-old with palpitations. Resting ECG shows slurred and brought up stroke of QRS complex and QRS widening. Which of the following is most likely present?
a. Accessory bypass tract connecting the atria and ventricles
b. Cardiac conduction system degeneration below the level of the atrioventricular node.
c. Ectopic atrial foci that serves as a dominant pacemaker.
d. Prolonged, ventricular action potential due to myocytes ion channel abnormality.
a. Accessory bypass tract connecting the atria and ventricles
dx = Wolff-Parkinson-White (WPW): ECG shows short PR interval + Delta waves (slurred upstroke of QRS) + QRS widening
May cause atrioventricular reentrant tachycardia (AVRT) – premature, atrial, or ventricular contraction creates a reentrant circuit involving the accessory pathway, and the atrioventricular node
name the four rotator cuff muscles and their functions and innervation
- Supraspinatus – adduction (15*), innervated by suprascapular nerve
- Infraspinatus – external rotation, innervated by suprascapular nerve.
- Teres minor – adduction and external rotation, innervated by axillary nerve.
- Subscapularis – adduction and internal rotation, innervated by subscapular nerve
32-year-old woman with mild shortness of breath on exertion for the past year. Was treated for anterior uveitis three months ago. Visual acuity is within normal limits. There is swelling of the parotid glands and the lungs are clear to auscultation. CXR reveals enlarged hilar lymph nodes and nodular pulmonary infiltrates. Diagnosis?
sarcoidosis - commonly occurs in younger, African-American patients
characterized on histology by non-caseating granulomas: collections of tightly clustered, epithelioid macrophages with abundant pink cytoplasm, surrounded by a rim of mononuclear cells without central necrosis
Primarily involves the lungs, causing nodular or interstitial infiltrates, however, extra pulmonary manifestations are common – hilar adenopathy, anterior uveitis, erythematous nodular rashes, neurosarcoidosis, heart and liver, parotid glands
obstruction of which coronary artery can result in atrioventricular block?
R coronary artery - in 90% of patients, RCA supplies AV node
RCA also supplies SA node —> blockage can cause sinus bradycardia
describe how Reye syndrome affects the brain
aspirin used in children during viral infection causes mitochondrial toxicity —> impaired fatty acid, metabolism and hyperammonemia (hepatic dysfunction)
Access ammonia accumulates and causes diffuse astrocyte swelling and cerebral edema
three day old patient with poor feeding, biliary emesis, and lethargy. Born via uncomplicated, spontaneous vagina delivery. Stool and urine output were normal while in the hospital. Patient is afebrile and normotensive, but tachycardic and tachypneic. Appears dehydrated and abdomen is distended. Laparotomy shows fibrous bands extending from the cecum and right colon to the retroperitoneum, causing extrinsic compression of the duodenum. What embryological process failed in this patient?
midgut rotation and intestinal fixation
At 4–8 weeks gestation, midgut (supplied by SMA) herniates through the umbilical ring while undergoing rapid growth that embryonic abdominal cavity cannot accommodate. During this process, midgut rotates 90° counterclockwise and then returns to abdominal cavity at 8–10 weeks, gestation, and turns an additional 180°. 270° counterclockwise total. intestines are then fixed to the parietal peritoneum of the posterior abdominal wall on a wide based mesentery. Incomplete rotation results in duodenal-jejunal flecture and cecum both resting in the right upper quadrant and fibrous bands connect the cecum to the retroperitoneum bypassing over the second part of the duodenum. These bands can compress the duodenum leading to symptoms of intestinal obstruction.
20 year old woman with PMH of primary hypothyroidism treated with levothyroxine, which has not been taken for two days because of vomiting, presents with intractable vomiting. BP is 80/40, pulse is 120, respirations are 18. Generalized hyper-pigmentation is present over face, neck, and dorsal surface of hands. Fingerstick blood glucose is 60. The patient requires immediate treatment with what type of medication?
Glucocorticoids (hydrocortisone, dexamethasone) - patient is experiencing acute adrenal crisis,
history of hypothyroidism (autoimmune) puts her at risk for other autoimmunities (such as of adrenal gland)
missing dose of levothyroxine for 2 days would not cause symptoms, and at that symptoms would be of hypothyroidism (hypoglycemia, hypotension, but also bradycardia, hypothermia, hypoventilation)
which of the following laboratory test should be obtained prior to starting a patient on metformin?
a. Blood cell counts and mean corpuscular volume.
b. Oral glucose tolerance test.
c. Plasma lactate level.
d. Serum creatinine level.
e. serum potassium level.
f. Serum TSH level.
d. Serum creatinine level.
inhibition of gluconeogenesis by metformin result in increased lactate production - patients with renal dysfunction or other disorders that reduce lactate clearance are at risk for metformin-induced lactic acidosis… GFR should be estimated using serum, creatinine measurement
Name two ovulation induction agents and describe their method of action
treat anovulatory infertility by increase FSH and LH
- letrozole: inhibits ovarian aromatase, preventing excess androgen to estrogen conversion —> less negative feedback on GnRH
- clomiphene: binds/depletes hypothalamic/pituitary estrogen receptors, decreasing negative feedback on GnRH release
52yo immigrant M presents w/ several days of vague chest pain and cough. PE reveals decrescendo diastolic murmur over RSB. Serum fluorescent treponemal antibody absorption testing is positive. CXR shows mediastinal widening. The pathological process responsible for this patient’s symptoms starts as which of the following?
a. Intimal streak.
b. Intimal tear
c. Medial degeneration.
d. Medial inflammation
e. vasa vasorum obliteration.
e. vasa vasorum obliteration.
murmur = aortic regurgitation, which in presence of mediastinal widening suggests aortic aneurysm (dilated aortic annulus)
+syphilis test indicates tertiary syphilis - begins with vasa vasorum endarteritis and obliteration —> inflammation, ischemia, weakening of adventitia —> aneurysmal dilation of thoracic aorta which can extend to involve aortic valve ring
schizophrenia is due to increased dopamine activity in the ______ pathway
mesolimbic pathway: projects from ventral tegmental area (VTA) to limbic system
state the function of the following dopamine pathways:
a. nigrostriatal
b. mesolimbic
c. tuberoinfundibular
a. nigrostriatal: substantia nigra to basal ganglia, involved in coordination of movement
b. mesolimbic: VTA to limbic system, excess signaling causes positive psychotic symptoms
c. tuberoinfundibular: hypothalamus to pituitary gland, inhibits prolactin release from anterior pituitary
which of the following is a protective factor against C. difficile infection?
a. Adequate pancreatic enzyme secretion.
b. intact cell mediated immunity.
c. Preformed anti-spore immunoglobins.
d. preserved intestinal Microbiome.
e. Rapid gastrointestinal transit and expulsion of spores.
d. preserved intestinal Microbiome - intestinal bacteria effectively suppress overgrowth of C. diff. infections in healthy patients
alteration of microbiome most commonly occurs via antibiotic therapy, but can also occur by gastric acid suppression (PPI)
C. diff. causes disease by releasing 2 toxins that damage the mucosal lining of the large intestine, leading to diarrhea (toxin A) and necrosis (toxin B) with pseudomembrane formation
contrast the presentation of cauda equina syndrome and pudendal nerve injury
Cauda equina syndrome: results from compression of spinal nerve roots below the level of the conus medullaris, presents with severe unilateral or bilateral radicular pain, saddle anesthesia, and lower extremity weakness and hyporeflexia
Pudendal nerve injury: results from excessive stress on the pelvic floor during labor and delivery, presents with new onset fecal incontinence due to denervation and weakness of the external anal sphincter
which congenital GI defect is due to failure of recanalization within the intestines?
duodenal atresia (double-bubble sign): early in gestation, epithelial proliferation briefly occludes the GI lumen and is followed by recanalization - failure to recanalize causes duodenal atresia with obstruction
high risk for Down syndrome patients
7yo M presents w/ facial puffiness especially noticeable in the morning. PMH of mild, intermittent asthma controlled w/ albuterol as needed. PE shows bilateral LW pitting edema. Nephrotic-range proteinuria consisting mainly of albumin. Which of the following mechanisms is most likely?
a. impaired tubular reabsorption of filtered proteins
b. increased filtration of plasma proteins
c. inflammation of urinary tract
b. increased filtration of plasma proteins - via effacement of podocyte food processes
dx = minimal change disease (most common nephrotic syndrome in children!!)
35yo M presents after falling off moving tractor. Over next few hours, he develops worsening pain and rapidly swelling in injured leg. Crepitus is present on PE, and imaging shows gas in tissues. Pathogen most likely responsible is also commonly associated with:
a. heart murmur and valve abscess
b. persistent cough and pharyngeal exudates
c. relentless headache and nausea
d. transient watery diarrhea and abdominal discomfort
d. transient watery diarrhea and abdominal discomfort
dx = Clostridium perfringens: Gram+ bacillus responsible for ~95% of gas gangrene, inoculates via penetrating injuries
can also cause late-onset food poisoning characterized by transient watery diarrhea (via toxin formed when spores are ingested)
Patient is discovered to have missense mutation in VHL gene. Periodic surveillance via which of the following is most beneficial?
a. bone marrow evaluation
b. chest radiography
c. colonoscopy
d. echocardiography
e. plasma metanephrines
e. plasma metanephrines
VHL (Von Hippel-Lindau): AD LOF mutation in VHL gene, ch.3 (tumor suppressor)
—> increased risk of cerebellar and retinal hemangioblastomas + pheochromocytoma + renal clear cell carcinoma
monitor with eye exam, plasma/urine metanephrines, MRI of brain/spine and abdomen
