NBME Exam 18 Corrections 100% Solved

Male newborn delivered at 28 weeks, neonatal respiratory distress syndrome, ABG shows decreased pH, decreased Po2 increased PCO2. A deficiency in which of the following most likely caused the disorder? A. Diacylglycerol B. Dipalmitoylphosphatidylcholine C. Phosphatidylserine D. Sphingomyelin E. Surfactant protein D - ANSWER-B. Dipalmitoylphosphatidylcholine Most important lecithin in pulmonary surfactant! so deficiency in it would lead to neonatal respiratory distress syndrome with ground glass appearance of lung fields 35-year-old woman with fever and sharp chest pain for 3 days. T 101.3F. Friction rub heard. All causes of secondary pericarditis ruled out. Cause of primary pericarditis? A. Bacterium B. Fungus C. Parasite D. Tumor E. Virus - ANSWER-E. virus (idiopathic but presumed to be viral) Researching new cancer drug, effective at killing rapidly dividing cells, in mice caused profound myelosuppression. In patients, most appropriate to follow which when at risk for infectious complications? A. Cytotoxic T-lymphocyte activity B. Natural killer cells C.Neutrophil counts D. Serum complement concentrations E. Serum IG concentrations - ANSWER-C. Neutrophil counts Make up majority of WBC! A part of the first responding innate immunity! Myelosuppression means no Myeloid cells like monocytes, macrophages, neutrophils, basophils, eosinophils, erythrocytes, dendritic cells, and megakaryocytes or platelets Patient with orthostatic hypotension, loose stools for 1 year, and history of type 1 DM. Stool studies are normal. What is the pathophysiological mechanism of the diarrhea? A. Exudation B. Generalized malabsorption C. Motility disorder D. Osmosis - ANSWER-C. Motility disorder DM nephropathy of the nerves so can control motility as well Full-term newborn in respiratory distress. Imaging shows abdominal contents in left pleural cavity. Maldevelopment of which structure led to diaphragm defect? A. Esophageal mesoderm B. Left diaphragmatic crus C. Left pleuropericardial fold D.Left pleuroperitoneal membrane E. Septeum transversum - ANSWER-D. Left pleuroperitoneal membrane Defect in it leads to diaphragmatic hernia where abdominal structures enter thorax. More prone to happen on the left side bc right hemidiaphragmn is relatively protected by liver 56-year-old exposed to possible chemical attack. Respirations labored, diaphoresis, excessive lacrimation, increased salivation, muscle strength 2/5, urinary and fecal incontinence. Besides atropine, another tx? A. Bethanechol B Phenoxybenzamine C. Pralidoxime D. Pyridostigmine - ANSWER-C. Pralidoxime ( regenerates AchE if given early) Phenoxybenzamine= irreversible alpha blocker used pre-op for pheochromocystoma to prevent catecholamine ( hypertensive) crisis Pyridostigmine= tx for myastenia gravis 46. 34-year old man is brought to the ER semiconscious and combative. In addition to sedation , a short-acting neuromuscular blocking agent is administered for intubation to prevent aspiration. Within a few seconds after admin of the drug, he has transient muscle fasciculations in his face ; he develops generalized paralysis within 1 minute. Forty five minutes after completion of the procedure , he is still paralyzed. A genetic abnormality of which of the following enzymes is the most likely cause of his unusually slow recovery from paralysis? A. Choline O-acetyltransferase B. Monoamine oxidase C. Phenylethanolamine N-methyltransferase D. Pseudocholinesterase - ANSWER-D. Pseudocholinesterase Pseudocholinesterase deficiency is a condition in which a person's body is abnormally slow at breaking down a certain class of drugs used for surgical anesthesia. Known as choline esters, the most commonly used of these drugs is called succinylcholine (suxamethonium). Different from malignant hyperthermia where person presents w/fever and muscle contractions and its due to mutation in voltage sensitive ryantodine receptor causing an increase in Ca release from sarcoplasmic reticulum 66-year-old woman is brought to the emergency department by her daughter because of a 2-day history of fever, flank pain, pain with urination, and nausea. Ten days ago, she was admitted to the hospital for similar symptoms and was diagnosed with acute pyelonephritis. She was discharged with instructions to take oral ciprofloxacin after a 3-day course of intravenous ciprofloxacin resulted in improvement. She also has hypertension, hyperlipidemia, and osteoporosis. Current medications also include alendronate, calcium carbonate, ezetimibe, hydrochlorothiazide, and simvastatin. Her temperature is 39.1°C (102.4°F), and blood pressure is130/80 mm Hg. The most likely cause of this patient's current condition is an interaction between her current oral antibiotic and which of the following medications? A. Alendronate B. Calcium Carbonate C. Ezetimibe D. Hydrochlorothiazide - ANSWER-B. Calcium Carbonate= can chelate and decrease effectiveness of other drugs ( like abx) 45-year-old man comes to the physician because of an enlarging face shoulders and trunk and thinning of his arms and legs. Physical examination shows a large plethoric face, fat pad over the upper thoracic spine and purple striae on the abdomen. Serum studies show undetectable ACTH and an increased cortisol concentration. Administration of low dose dexamethasone would most likely result in which of the following sets of serum findings? A. ACTH= No change and Cortisol= Increased B. ACTH= No change and Cortisol= no change C. ACTH= No change and Cortisol= decreased - ANSWER-B. ACTH= No change and Cortisol= No change Dexamethasone is supposed to provide negative feedback to pit suppressing ACTH secretion so more cortisol wont be produced but it not making a change means this process is outside the normal axis. ACTH is undetectable so ACTH independent Cushings syndrome (so doesnt involve the anterior pit) Most likely either exogenous glucocorticoids or adrenal tumor! 71-year old woman with coronary disease and well-controlled hypertension is brought to the physician 2 hours after sudden onset of weakness of her left leg. Her BP 145/85 mmHg. Neurologic exam: weakness and decreased sensation over the left lower extremity. There are no other sensory or motor deficits. Which labeled structure is site of injury? - A (Pre/postcentral gyrus; motor/sensory cortex) - ANSWER-Only Lower Limb sensory loss and weakness- Anterior cerebral artery infarct which impacts the motor/sensory cortex 11. 14-year-old girl with type 1 diabetes mellitus and 4-hour history of lethargy, confusion, disorientation. Symptoms gradually developed and she did not take her usual insulin dose during a sleepover. HR 110, RR 24 deep and rapid, bp 95/75. Labs: glucose 450, arterial pH 7.15. ABG? pCO2/HCO3-/Anion gap - decreased/decreased/increased - ANSWER-Diabetic ketoacidosis= metabolic acidosis so primary disturbance is going to be a decrease in arterial HCO3! Due to hyperventilation will have decreased PCO2 and increased anion gap Studying epithelial repair of small intestine in experimental animal. Wants to identify most active cell division location. Where is this cell activity found? A.Base of the crypt B. Brunner gland C. Peyer Patch D. Top of the villi - ANSWER-A. Base of the crypt (contain stem cells that replace enterocytes/ globlet cells) 67-year-old man with 3 months fatigue and shortness of breath. Vitals HR 90, RR 15, bp 150/98. PE conjunctival pallor. Labs: hb 8.5, hct 26%, MCV 90, RDW 14.4% (N=13-15%), Cr 2.9, Ferritin 144, Iron 24, Transferrin saturation 23% (N=20-50%). Besides iron supplementation, most appropriate tx? A. Erythropoietin B. Folic Acid C. Granulocyte colony- stimulating factor - ANSWER-A. Erythropoietin Creatinine is high!! So something is going on with the kidney! 18-month-old girl with 2 day progressive cough and hoarseness. T 102.2F, HR 88, RR 24, bp 100/70. Oxygen saturation 95%. PE mild erythema of oropharyngeal and laryngeal mucosa no exudate, harsh, barking cough heard. Improves within 4 days. Cause? A. Bordetella pertussis B. Influenza A virus C. Parainfluenza virus D. RSV - ANSWER-C. Parainfluenza Virus Harsh barking cough= croup! So parainfluenza virus! RSV= bronchiolitis To decrease risk for cv disease 24 yo man begins diet. 1.53 cm 95 kg BMI 32, Intends to lose 16 kg by limiting caloric intake to 2000 cal. to maintain the recommended protein intake (56g day); a balanced decreased in carbs and fat is required (caloric radio of fat and carbs is 30:55). which best describes number of calories that should be provided by fat in this its diet each day? A. 370 B. 430 C. 510 D. 630 E. 740 - ANSWER-D. 630 1g carb or protein= 4kcal 1g alcohol= 7kcal 1g Fatty acid=9 kcal 56*4= 224 cal for protein 2000-224= 1776 cal for fat and carbs 30:55 (fat: carb) so 30/85= X/1776 x=626 41. 65-year-old woman comes to the physician because of a 1-week history of a swollen, painful left knee. Her temperature is 38°C (100.4°F), and blood pressure is 110/65 mm Hg. Examination of the left knee shows erythema and swelling of the joint and decreased range of motion. A photomicrograph of synovial fluid obtained by arthrocentesis is shown. This patient's synovial fluid most likely contains which of the following? A. Uric acid B. Neisseria gonorrhoeae C. Treponema pallidum - ANSWER-A. Uric Acid Monosodium urate crystal on photomicrograph of synovial fluid. S.aureus, strep, N. gonorrhoeae ( synovial fluid has lots of WBC! and is purlent!) 25-year-old woman with fatigue for 3 wks and intermittent fever for 7 days, had teeth cleaned a month ago, no abx for prophylaxis, and had rheumatic fever as child and endocarditis 4 y ago. PE shows 2/6 murmur, ultrasound shows abnormal mitral valve. Photo of growth from blood cultures shown (GP cocci in chains). Characteristic of causal organism? A. Greening reaction on blood agar B. Inhibition by optochin C. Resistance to novobiocin - ANSWER-A. Greening reaction on blood agar bc alpha hemolytic!! optochin resistant! and catalase negative Strep Viridans! 65-year-old man with 4-hour history of intermittent severe pain in flank area radiating to genital region. History of hypercalciuria and renal calculi. Drug decrease the urinary excretion of calcium? A. Acetazolamide B. Furosemide C.Hydrochlorothiazide D. Spironolactone - ANSWER-D. Hydrocholorothiazide MOA: inhibits NaCl re-absorption of in early DCT- decreasing diluting capacity of the nephron. Decreases Ca excretion! A 25-year-old man is admitted to the hospital because of severe crush injuries to the chest and extensive burns over 30% of his body surface area. Three hours later, he develops tachypnea and dyspnea. Arterial blood gas analysis on room air shows a decreased Po2 and Pco2. A chest x-ray shows bilateral interstitial and alveolar infiltrates. The patient is intubated and mechanically ventilated. Damage to which of the following is most likely to preclude restoration of normal tissue architecture and pulmonary function in this patient? A. Basement membranes B. Capillaries C. Fibroblasts D. Macrophages E. Mast cells - ANSWER-Preclude= prevent from happening! A. Basement membrane (interstium btw the alveoli and the capillari) damage to this would lead to fibrosis and scarring reducing pulmonary function Acute respiratory distress syndrome 19-year-old woman is admitted to the hospital for antibiotic treatment of meningococcal meningitis. She is stabilized. Three days later, her pulse is 120/min, and blood pressure is 60/30 mm Hg. Physical examination shows bilateral flank tenderness. Serum studies show a sodium concentration of 128 mEq/L, potassium of 5.4 mEq/L, and bicarbonate of 20 mEq/L. Which of the following is the most appropriate next step to determine the cause of this patient's hypotension? A.Adrenocorticotropic hormone stimulation test B. Blood culture and antibiotic sensitivity test C. Urine culture and antibiotic sensitivity test - ANSWER-A. Adrenocorticotropic hormone stimulation test. To see how well adrenal glands respond to ACTH! Decrease in Na and bicarb and increase in potassium s/p meningococcal meningitis= Waterhouse-Friderichsen syndrome: acute primary adrenal insufficiency due to adrenal hemorrhage associated with septicemia Adrenal insufficiency= deficiency of aldosterone and cortisol ( mineralcorticoids and glucocorticoids) 2-month-old female with T 102F, vomiting, diarrhea, dehydration. Exam of stool shows viral particles with wheel-like shape. Properties of virus? Type of nucleic acid/envelop/capsid symmetry - Double-stranded RNA, segmented/no/icosahedral - ANSWER-- Double-stranded RNA, segmented/no/icosahedral Rotavirus! #1 cause of infantile gastroenteritis and fatal diarrhea in kids 32-year-old woman has new neuro finding while being tx for acute infection of sphenoid sinus. Imaging shows cavernous sinus thrombosis on left. Additional finding most likely? A. Central facial weakness B. Decreased sense of smell C. Inability to abduct the eye - ANSWER-C. Inability to abduct the eye CN that pass thru cavernous sinus and could be impacted CN III (eye movement and pupil constriction) CN IV (eye movement) CN V1 (afferent nerve of lacrimation reflex) CN VI ( eye movement laterally) 83-year-old with arteriosclerosis undergoes repair of infrarenal abdominal aortic aneurysm. Graft extends just below the renal arteries to the bifurcation of the aorta. Which organ will lose primary blood supply and rely on collateral circulation? A. Adrenal gland B. Descending colon C. Pancreas D. Spleen - ANSWER-B. Descending colon Branches off the abdominal aorta (Superior to inferior) Celiac trunk SMA Renal Gonadal (on left side) IMA Bifurcation at L4 in to Left and Right common illiacs! IMA supplies (Hindgut) Distal 1/3 of transverse colon to upper portion of the rectum. 39-year-old man with polycystic kidney disease has 6-month history intermittent blood in urine. T 98.6 F HR 100 RR 24 BP 160/90. Urea nitrogen 100, creatinine 8. UA shows blood. Arterial blood gas shows? pH/pCO2/HCO3- - 7.22/28/11 - ANSWER-Increase in creatinine and BUN-- renal failure Consequence of renal failure= Metabolic acidosis so Bicarb will be 20 and PCO2 will be decreased too due to hyperventilation. 48-year-old man 2-month increasing abdominal girth and inability to achieve erection. Smoked 1 pack cigarettes for 20 years and drug 1 pint of liquor daily. Vitals normal. PE shows scleral icterus, spider angiomata, gynecomastia, ascites and prominent umbilical venous pattern. Tests small. Cause of gynecomastia? A. Excessive estrogen production by the adrenal glands B. Failure of liver to conjugate testosterone to its carrier molecule C.Failure of liver to degrade estrogen - ANSWER-C. Failure of liver to degrade estrogen Liver cirrhosis leads to gynecomastia Estrogen stimulates breast development! 19-year-old man with gastrointestinal bleeding. Laparotomy done and 5-cm blind outpouching on antimesenteric side of terminal ileum 15 cm from ileocecal valve resected. Pathology shows? A. Angiodysplasia of the colon B. Crohn disease C. Heterotopic gastric mucosa - ANSWER-C. Heterotopic gastric mucosa Meckel's Diverticulumn= partial closure of the vitelline duct w/ patent portion attached to ileum (blind pouch with opening to illeum). May have heterotopic gastric or pancreatic tissue-- melena, hematochezia, abdominal pain. About 2 feet away from illeoceccal valve 68-year-old man with creatinine 2.3 due to chronically increased hydrostatic pressure in Bowman space. Cause? A. Benign prostatic hyperplasia B. Congestive Heart Failure C. Hypertension D. Type 2 Diabetes - ANSWER-A. Benign Prostatic Hyperplasia BPH is an obstruction of male urinary tract! Outflow obstruction has potential to create hydronephrosis or post renal azotemia. Back pressure of urine will lead to increased hydrostatic pressure in bowman's space. Child with XXY karyotype, genetic studies showed he received the extra "x" from his father. An error of chromosome segregation occurred during anaphase at which of the following stages of spermatogenesis in the patient's father? A. Early spermatid B. Late spermatid C.Primary spermatocyte D. Primodrial germ cell E. Secondary spermatocyte - ANSWER-C. Primary spermatocyte Diploid so 2N! (X-X Y-Y) Primary spermatocyte goes thru meiosis I to become secondary spermatocyte haploid so 1N (X-X) or (Y-Y) 50-year-old woman with COPD comes with 3 months of progressive shortness of breath. Physical shows JVD, loud pulmonary component of S2. Pulmonary function tests show FEV1:FVC ratio of 20% and decreased diffusing capacity for carbon monoxide. Which is decreased in pulmonary vascular smooth muscle? A. Adventitial collagen matrix deposition B. Cytosolic phospolipase A2 activity C. Endothelial nitric oxide synthase production D. Endothelin expression - ANSWER-C. Endothelial nitric oxide synthase producition COPD- Hypoxemia-Alveoli constrict in attempt to send blood to more diffused part of lung)- high pressure in pulmonary circuit- atherosclerosis of pulmonary trunk, smooth muscle hypertrophy of pulmonary arteries, & intimal fibrosis so less vasodilation happening and less endothelial nitric oxidase synthase production 25-year-old woman with polycystic kidneys and 3-month history of weakness, fatigue, headaches, hypertension, loss of appetite and itching. Cr 4. Labs? - bicarb (HCO3-) decreased, inorganic phosphorous (PO4) increased, parathyroid hormone increased - ANSWER-Chronic renal disease--(Renal osteodystrophy) secondary hyperparathyroidism-- Hypocalcemia, hyperphophatemia, failure of vit d hydroxylation (decreased ca intestinal absorption) Renal failure: Metabolic acidosis (decrease in bicarb) and renal osteodystrophy Patient making sexual advances towards physician. Appropriate measure? A. Have a chaperone join them B. Stop the history taking and refer the patient to another physician - ANSWER-A. Have a chaperone join them 65-year-old with sudden onset generalized tonic-clonic seizures. Personality change last 6 months; used to be mild mannered and now verbally abusive. CT shows single mass enhances with contrast in right frontal lobe and crosses to left hemisphere through corpus callosum. Dx? A. High-grade fibrillary astrocytoma B. Malignant meningioma C. Metastatic carcinoma D. Metastatic melanoma - ANSWER-A. High grade fibrillary astrocytoma Astrocytoma= Glioblastoma multiforme Agressive malignant tumor found in cerebral hemisphere can cross cropus callosum! Mets present as multiple well circumscribed lesions at the gray white junction 67-year-old woman with atrial fibrillation with sudden onset severe abdominal pain. Ex-lap shows embolus in superior mesenteric artery with complete occlusion of middle colic artery. Ischemic changes where? A. Descending colon, sigmoid colon, and rectum B. Distal one third of the esophagus, stomach and duodenum C. Small intestine, ascending colon, and part of the transverse colon D. Stomach duodenum, and small intestine - ANSWER-C. Small Intestine, ascending colon, and part of the transverse colon. SMA: Midgut! so distal duodenumn to proximal 2/3 of transverse colon. Celiac trunk: foregut! so Pharynx and lower esophagus to proximal duodenum, liver, gallbladder, pancreas, spleen! 60-year-old man 1 day of fever, chills, confusion and memory loss. Returned from Gulf coast where he walked barefoot. Hx of severe cirrhosis and portal hypertension. T 39C (102.2 F), RR 22, bp 90/48. Physical shows early blister formation on right lower extremity. Blood culture: gram-negative, lactose-fermenting organism. Bug? A. Haemophilus influenzae B. Salmonella typhi C. Vibrio vulnificus - ANSWER-C. Vibrio vulnificus V. vulnificus can cause a wound infection from contact with contaminated water or shellfish. Salmonella is not a lactose fermenting organism Haemophilus influenzae is a respiratory gram negative that lactose fermenting doesnt test for. An experimental animal is created that has a defect in an innate gastrointestinal defense mechanism. Organism is found to have decreased HCl prod. After 2 months on biopsy gastric fundus and body show decreased mucosal thickness and hyperplasia of enterochromaffin like cells. This closely resembles? A. Barrett esophagus B. Chronic gastritis C. Whipple disease D. Zollinger- Ellison syndrome - ANSWER-B. Chronic gastritis Decreased HCL production-hypergastrinemia (high gastrin) increases acid secretion primarily thru its effects on enterochromaffin like cells (hyperplasia) and mucosal inflammation 35-year-old woman with 3-month progressive shortness of breath with exertion. RR 26. Physical shows jvd and prominent a wave. Lungs clear. Cardiac exam shows loud pulmonic component of S2 and right-sided S4 gallop. Increased pulmonary expression of what? A. Endothelin-1 B. Nitric oxide C. Prostacyclin D. Thrombomodulin - ANSWER-A. Endothelin-1 Causes vasoconstriction that plays a role in pulmonary hypertension and cor pulmonale 30-year-old woman with 2-years of numbness, blanching, and bluish color to ears, fingers and toes after emotional upset or cold exposure. Vitals and PE normal. Avoid taking which drug? A. Acetaminophen B. Dextromethorphan C. Diphenhdramine D. Phenylephrine - ANSWER-D. Phenylephrine= Alpha adrenergic agonist: increase in vasoconstriction