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1 SAMPLE TEST QUESTIONS Step 1 A Joint Program of the Federation of State Medical Boards of the ® United States, Inc., and the National Board of Medical Examiners

2 This booklet was updated February 2019. Copyright © 2019 by the Federation of State Medical Boards of the United States, Inc. (FSMB), and the National Board of Medical ® ® Examiners (NBME ). All rights reserved. Printed in the United States of America. The United States Medical Licensing ® Examination (USMLE ) is a joint program of the FSMB and the NBME. 1

3 CONTENTS USMLE Step 1 Test Question ... 3 Formats ... Sample Test Questions ... ... Introduction to USMLE Step 1 4 Normal Laboratory Values ... ... 5 USMLE Step 1 Sampl e Test Questions... ... 7 for USMLE Step 1 Sample Test Questions... ... 4 4 Answer Form Answer Key for USMLE Step 1 Sample Test Questions... . 4 5 2

4 USMLE S TEP 1 TEST QUESTION FORMATS Single - Item Questions - centered vignette is associated with one question followed by four or more response options. A single patient The res interpretation of graphic A, B, C, D, E). A portion of the questions ponse options are lettered ( require orial materials. You are required to select the best answer to the question. Other options may be or pict - partially correct, but there is only ONE BEST answer. This is the traditional, most frequently used multiple choice question format on the examination. Best - egies for Answering Single One Strat - Answer Test Questions best - answer items: The following are strategies for answering one -  Read each patient vignette and question carefully. It is important to understand what is being asked. Try to generate an answer a nd then look for it in the response option list.  Alternatively, read each response option carefully, eliminating those that are clearly incorrect.  Of the remaining options, select the one that is most correct.  If unsure about an answer, it is better to gue ss since unanswered questions are automatically counted  as wrong answers. Example Item - - A 32 old woman with type 1 diabetes mellitus has had progressive renal failure over the past 2 years. She year has not yet started dialysis. Examination shows no abnormalities. Her hemoglobin concentration is 9 g/dL, 3 hematocrit is 28%, and mean corpuscular volume is 94 μm . A blood smear shows normochromic, normocytic cells. Which of the following is the most likely cause? (F) Microangiopathic hemolysis Acute blood loss (A) (G) Polycythemia vera (B) Chronic lymphocytic leukemia (C) Erythrocyte enzyme deficiency Sickle cell disease (H) (D) Erythropoietin deficiency (I) Sideroblastic anemia Immunohemolysis β (E) (J) - Thalassemia trait (Answer: D) it ems provided NOTE: Some item types that appear on the Step 1 examination are NOT depicted in the sample in this booklet, eg items with multimedia features, such as audio . Also , when additional item formats are , will be provided at the USMLE web site: http:// www.usmle.org . You must monitor added to the exam, notice site to stay informed about the types of items that occur in the exam, and must practice with the you the web t items available on the USMLE web site to be fully prepared for the examination. downloadable sample tes 3

5 I NTRODUCTION TO USMLE STEP 1 SAMPLE TEST QUESTIONS sample test questions. Most of these questions are the same as those you The following pages include 117 can install o n your computer from the USMLE web site. Please note that reviewing the sample questions as they 4 - 3 appear on pages 7 is not a substitute for practicing with the test software. You should download and run that are provided on the USMLE w the Step 1 tutorial and practice test items ebsite well before your test date. The sample materials available de additional items and item formats that do not on the USMLE web site inclu appear in this booklet, such as items with associated audio or video findings. You should become familiar with all item formats that will be used in the actual examination. examination , they may not reflect the overall Although the sample questions exemplify content on the Step 1 content coverage on individual examinations. In the actual examination, questions will be presented in tent. The questions will be presented one at a random order; they will not be grouped according to specific con f the Normal Laboratory Values t able time in a format designed for easy on - screen reading, including use o re not of rays in this booklet a - (included here on pages 5 and 6) and some pictorials. Photographs, charts, and x the same quality as the pictorials used in the actual examination. In addition, you will be able to adjust the brightness and contrast of pictorials on the computer screen. To take the following sample test questions as they would be timed in the actual examination, you should for the 37 - item allow a maximum of 1 hour for each 40 - item block, and a ma ximum of 55 minutes, 30 seconds, nstead of Please note that the third block has 37 items i block, for a total of 2 hours, 55 minutes, 30 seconds. 40 because the multimedia items have been removed, and the recommended time to complete the block has been adjusted accordingly. Please be aware that most examinees perceive the time pressure to be greater ees are strongly encouraged to practice with the downloadable during an actual examination. All examin An answer form for recording answers is version to become familiar with all item formats and exam timing. . In the actual examination, an swers will be . An answer key is provided on page 4 provided on page 4 4 5 selected on the screen; no answer form will be provided. 4

6 LABORATORY VALUES INTERVALS REFERENCE RANGE SI REFERENCE BLOOD, PLASMA, SERUM ... 8 - 20 U/L ... ... 8 - 20 U/L Alanine aminotransferase (ALT), serum ... 25 - 125 U/L ... ... 25 - 125 U/L Amylase, serum ... ... 8 - 20 U/L ... ... 8 - 20 U/L Aspartate aminotransferase (AST), serum 0.1 - 1.0 mg/dL // 0.0 - 0.3 mg/dL ... 2 - 17 μmol/L // 0 - 5 μmol/L Bilirubin, serum (adult) Total // Direct ... 2+ Calcium, serum (Ca ... ... 8.4 - 10.2 mg/dL ) ... 2.1 - 2.8 mmol/L ... Cholesterol, serum ... ... Rec:<200 mg/dL ... ... <5.2 mmol/L Cortisol, serum ... ... 0800 h: 5 - 23 μg/dL // 1600 h: 3 - 15 μg/dL 138 - 635 nmol/L // 82 - 413 nmol/L 50% of 0800 h ... Fraction of 0800 h: < 0.50 2000 h: < ... ... Male: 25 - 90 U/L ... 25 - 90 U/L Creatine kinase, serum ... 70 U/L ... ... 10 - 70 U/L Female: 10 - Creatinine, serum ... ... 0.6 - 1.2 mg/dL ... ... 53 - 106 μmol/L Electrolytes, serum + ) ... ... 136 - ... ... 136 - 145 mmol/L Sodium (Na 145 mEq/L + Potassium (K - ) ... ... 3.5 - 5.0 mEq/L ... ... 3.5 5.0 mmol /L – Chloride (Cl ) ... 95 - 105 mEq/L ... ... 95 - 105 mmol/L ... – Bicarbonate (HCO ... ... 22 - 28 mEq/L ) ... ... 22 - 28 mmol/L 3 2+ ... ... 1.5 - 2.0 mEq/L ... ... 0.75 - 1.0 mmol/L ) Magnesium (Mg Estriol, total, serum (in pregnancy) - 28 wks // 32 - 36 wks ... ... 30 - 170 ng/mL // 60 - 280 ng/mL ... 104 - 590 nmol/L // 208 - 970 nmol/L 24 28 32 wks // 36 - 40 wks ... ... 40 - 220 ng/mL // 80 - 350 ng/mL ... 140 - 760 nmol/L // 280 - 1210 nmol/L - Ferritin, serum ... ... Male: 15 - 200 ng/mL ... . 15 - 200 μg/L - Female: 12 ... 12 - 150 μg/L 150 ng/mL Follicle stimulating hormone, serum/plasma ... Male: 4 - 25 mIU/mL ... .. 4 - 25 U/L - 30 mIU/mL ... 4 - 30 U/L Female: premenopause 4 - 10 midcycle peak 10 ... 90 mIU/mL - 90 U/L - postmenopause 40 - 250 mIU/mL ... 40 - 250 U/L ood (room air) Gases, arterial bl + pH ... ... ... 7.35 - 7.45 ... ... [H ] 36 - 44 nmol/L - ... ... ... 33 CO 45 mm Hg ... ... 4.4 - 5.9 kPa P 2 P O 14.0 kPa ... ... ... 75 - 105 mm Hg ... ... 10.0 - 2 Glucose, serum ... ... Fasting: 70 - 110 mg/dL ... 3.8 - 6.1 mmol/L 2 - ... < 6.6 mmol/L h postprandial: < 120 mg/dL Growth hormone arginine sti mulation ... Fasting: < 5 ng/mL ... ... < 5 μg/L - > 7 μg/L ... provocative stimuli: > 7 ng/mL Immunoglobulins, serum ... ... - 390 mg/dL IgA ... ... 0.76 - 3.90 g/L ... 76 ... ... ... 0 - 380 IU/mL ... ... 0 380 kIU/L IgE - IgG ... ... ... 650 - 1500 mg/dL ... ... 6.5 - 15 g/L ... ... ... 40 - 345 mg/dL ... ... 0.4 - 3.45 g/L IgM Iron ... ... ... 50 - 170 μg/dL ... 9 - 30 μmol/L ... ctate dehydrogenase, serum ... . 45 - 90 U/L ... ... 45 - 90 U/L La Luteinizing hormone, serum/plasma Male: 6 - 23 mIU/mL ... .. 6 - 23 U/L ... - ... 30 mIU/mL - 30 U/L Female: follicular phase 5 5 midcycle 75 - 150 mIU/mL ... 75 - 150 U/L postmenopause 30 30 200 mIU/mL ... - 200 U/L - Osmolality, serum - ... ... 2 75 - 295 mOsmol/kg H O ... 275 295 mOsmol/kg H O 2 2 Parathyroid hormone, serum, N - terminal ... 230 630 pg/mL ... ... 230 - 630 ng/L - Phosphatase (alkaline), serum (p - NPP at 30 ° C) ... 20 - 70 U/L ... ... 20 - 70 U/L ... . 3.0 - 4.5 mg/dL ... ... 1.0 - 1.5 mmol/L Phosphorus (inorganic), serum Prolactin , serum (hPRL) ... ... < 20 ng/mL ... ... < 20 μg/L Proteins, serum ... ... 6.0 - 7.8 g/dL ... ... 60 - 78 g/L Total (recumbent) Albumin ... ... 3.5 - 5.5 g/dL ... ... 35 - 55 g/L ... ... 2.3 - 3.5 g/dL ... ... 23 - 35 g/L Globulin ... Thyroid stimulating hormone, serum or plasma ... 0.5 - 5.0 μU/mL - ... 0.5 - 5.0 mU/L 123 T hyroidal iodine ( I) uptake ... ... 8% - 30% of administered dose/24 h ... 0.08 - 0.30/24 h Thyroxine (T ), serum ... ... 5 - 12 μg/dL ... ... 64 - 155 nmol/L 4 ... ... 35 - 160 mg/dL Triglycerides, serum ... ... 0.4 - 1.81 mmol/L Triiodothyronine (T ), serum (RIA) ... 115 - 190 ng/dL ... ... 1.8 - 2.9 nmol/L 3 Triiod othyronine (T ) resin uptake ... 25% - 35% ... ... 0.25 - 0.35 3 Urea nitrogen, serum ... ... 7 18 mg/dL ... ... 1.2 - 3.0 mmol/L - 0.48 mmol/L - Uric acid, serum ... ... 3.0 - 8.2 mg/dL ... ... 0.18 5

7 LABORATORY VALUES (continued ) SI REFERENCE INTERVALS REFERENCE RANGE BODY MASS INDEX (BMI) 2 Adult: 19 - 25 kg/m Body mass index ... ... CEREBROSPINAL FLUID 3 6 0 - 5/mm Cell count ... ... 0 - 5 x 10 /L ... ... .. ... ... ... - 132 mEq/L ... ... 118 - 132 mmol/L Chloride 118 Gamma globulin ... ... 3% - 12% total proteins ... ... 0.03 - 0.12 ... Glucose ... ... 40 - 70 mg/dL ... ... 2.2 - 3.9 mmol/L Press ure ... ... ... 70 - 180 mm H O ... ... 70 - 180 mm H O 2 2 <0.40 g/L <40 mg/dL ... ... ... ... Proteins, total HEMATOLOGIC ... 2 - 7 minutes ... ... 2 - 7 minutes Bleeding time (template) ... 3 12 ... ... Male: 4.3 - 5.9 million/mm 5.9 x 10 ... 4.3 - Erythrocyte count /L 3 12 5.5 x 10 ... 3.5 - - /L 5.5 million/mm Female: 3.5 E rythrocyte sedimentation rate (Westergren) ... Male: 0 - 15 mm/h ... ... 0 - 15 mm/h - 20 mm/h ... ... 0 - 20 mm/h Female: 0 Hematocrit ... ... Male: 41% - 53% ... ... 0.41 - 0.53 Female: 36% - ... ... 0.36 - 0.46 46% ... Hemoglobin A ... < 6% ... ... .. < 0.06 1c ... ... Male: 13.5 - 17.5 g/dL ... ... 2.09 - 2.71 mmol/L Hemoglobin, blood - 16.0 g/dL ... ... 1.86 - Female: 12.0 2.48 mmol/L ... ... 1 - 4 mg/dL ... ... 0.16 - 0.62 mmol/L Hemoglobin, plasma Leukocyte count and differential 9 3 ... ... 4500 - 11,000/mm ... ... 4.5 - 11.0 x 10 Leukocyte count /L Segmented neutrophils ... ... 54% - 62% ... ... 0.54 - 0.62 Bands ... ... ... 3% - 5% ... ... 0.03 - 0.05 Eosinophils ... ... 1% - 3% ... ... 0.01 - 0.03 Basophils ... ... 0% - 0.75% ... ... 0 - 0.0075 ... ... 25% - 33% ... ... 0.25 - 0.33 Lymphocytes Monocytes ... ... 3% - 7% ... ... 0.03 - 0.07 Mean corpuscular hemoglobin ... .. 25.4 - 34.6 pg/cell ... ... 0.39 - 0.54 fmol/cell ... 31% Mean corpuscular hemoglobin concentra tion 5.58 mmol Hb/L - 36% Hb/cell ... ... 4.81 - 3 ... ... 80 - 100 μm Mean corpuscular volume ... ... 80 - 100 fL ... Partial thromboplastin time (activated) 25 - 40 seconds ... ... 25 - 40 seconds 9 3 150 ... - 400,000/mm ... ... 150,000 - 400 x 10 Platelet count /L ... Prothrombin time ... ... 11 - 15 seconds ... ... 11 - 5 seconds 1 ... ... 0.5% - 1.5% ... ... 0.005 - Reticulocyte count 0.015 ... ... Thrombin time ... <2 seconds deviation from <2 seconds deviation from control ... ... ... ... ... control Volume ... Plasma ... ... Male: 25 - 43 mL/kg ... ... 0.025 - 0.043 L/kg - 45 mL/kg ... ... Female: 28 - 0.045 L/kg 0.028 ... ... ... Male : 20 - Red cell ... ... 0.020 - 0.036 L/kg 36 mL/kg Female: 19 - 31 mL/kg ... ... 0.019 - 0.031 L/kg SWEAT Chloride ... ... ... 0 - ... ... 0 - 35 mmol/L 35 mmol/L URINE 300 mg/24 h ... ... ... 100 - Calcium ... ... 2.5 - 7.5 mmol/24 h Chloride ... ... ... Varies with intake ... ... Varies with intake Creatinine clearance ... ... Male: 97 - 137 mL/min - 128 mL/min Female: 88 Estriol, total (in pregnancy) ... ... ... 6 - ... ... 21 - 62 μmol/24 h 30 wks 18 mg/24 h 35 wks ... ... ... 9 - 28 mg/24 h ... ... 31 - 97 μmol/24 h ... ... ... 13 - 42 mg/24 h ... ... 45 - 146 μmol/24 h 40 wks g/24 h Hydroxycorticosteroids ... ... Male: 3.0 - 10.0 m - ... ... 8.2 - 27.6 μmol/24 h 17 Female: 2.0 - 8.0 mg/24 h ... ... 5.5 - 22.0 μmol/24 h 17 Ketosteroids, total ... ... Male: 8 - 20 mg/24 h ... ... 28 - 70 μmol/24 h - - Female: 6 ... ... 21 - 52 μmol/24 h 15 mg/24 h - ... ... 50 1400 mOsmol/kg H O Osmolality 2 Oxalate ... ... ... 8 - 40 μg/mL ... ... 90 - 445 μmol/L aries with diet ... ... . V ... ... Varies with diet Potassium Proteins, total ... ... <150 mg/24 h ... ... <0.15 g/24 h Varies with diet ... ... ... Sodium ... ... Varies with diet Varies with diet Uric acid ... ... ... Varies with diet ... ... 6

8 USMLE STEP 1 SAMPLE TEST QUESTIONS - 40 BLOCK 1, ITEMS 1 A 28 - 1. - old man comes to the physician because of a 1 - year history of pain with urination that has increa sed in severity year years. He lived in sub - Saharan Africa during the past month. He also has had episodes of blood in his urine during the past 5 (100.4°F), pulse is 80/min, res pirations months ago for graduate school. His temperature is 38°C until he came to the USA 6 mm Hg. Physical examination shows suprapubic tenderness. Laboratory studies are 16/min, and blood pressure is 110/84 show: Hemoglobin 12.3 g/dL Hematocrit 37% 3 Leukocyte count 13,400/mm Segmented neutrophils 65% Bands 5% Eosinophils 5% 22% Lymphocytes Monocytes 3% Serum Urea nitrogen 75 mg/dL Creatinine 3.8 mg/dL Urine Blood 3+ RBC 200/hpf WBC 100/hpf RBC casts absent WBC casts absent Imaging studies show bilateral hydroureter and hydronephrosis and foci of calcification in the region of the bladder. A biopsy specimen of the bladder shows marked chronic inflammation with fibrosis and scattered granulomas. Which of the following best explains the biopsy findings? (A) Exposure to a chemical toxin (B) Interstit ial cystitis (C) Malacoplakia (D) Schistosomiasis (E) Vesicoureteral reflux 2. A 14 - year - old boy is brought to the emergency department after being hit with a baseball bat on the lateral side of his leg immediately below the knee. He is unable to dorsiflex his foot. Which of the following nerves is most likely injured? Common fibular (peroneal) (A) (B) Femoral (C) Obturator (D) Sural (E) Tibial 7

9 legs. Four days ago, - year - old man comes to the office because of a 2 - 3. A 24 day history of a red, itchy rash on his buttocks and he returned from a cruise to the Caribbean, during which he swam in the ship’s pool and used the hot tub. He appears well. His vital signs are within normal limits. Physical examination shows the findings in the photograph. The infecti ous agent causing these findings most likely began to proliferate in which of the following locations? (A) Apocrine gland (B) Dermis (C) Eccrine gland (D) Hair follicle (E) Sebaceous gland A 14 4. ther learned that she began having sexual intercourse with various old girl is brought to the physician after her mo - year - partners 1 month ago. She does not use condoms or other contraception. The mother is concerned about her behavior. The patient's parents separated 3 months ago. She had been an honor studen t and excelled in sports and leadership positions at school before the separation. Since the separation, however, she has become sullen, defiant, and rebellious. She has begun smoking cigarettes, disobeying her curfew, and being truant from school. This pa tient is most likely using which of the following defense mechanisms? (A) Acting out (B) Displacement (C) Projection (D) Reaction formation (E) Sublimation 8

10 5. year - old woman comes to the physician for a follow - up examination. One week ago, she was treated in the emergency A 24 - food restaurant. Examination of the department after she accidentally spilled hot grease on her left leg while working at a fast - left lower extremity shows a 7 - cm, pink, soft, granular, edematous wound. The formation of this tissu e was most likely caused by increased activity of which of the following? Complement C3b (A) - dependent cell adhesion molecule - 1 Glycosylation (B) P - selectin (C) Stromelysin (D) (E) Vascular endothelial growth factor old woman comes to the - year 6. A 63 physician 1 day after the sudden onset of pain and swelling of her right knee. She has had - no injury. Her medications include occasional ibuprofen for mild osteoarthritis of both knees. Her temperature is 37°C (98.6°F), pulse is 97/min, respirations are 19 /min, and blood pressure is 129/79 mm Hg. Examination of the right knee shows warmth, erythema, and effusion. Exquisite tenderness is produced with minimal range of - motion testing. Examination - of synovial fluid obtained via joint aspiration shows that it i s clear, with positively birefringent rhomboids observed under polarized light microscopy. Deposition of which of the following substances is the most likely cause of these findings? (A) Ammonium urate (B) Calcium oxalate (C) Calcium pyrophosphate Cal (D) cium urate (E) Sodium urate A 55 - year - 7. old woman with small cell carcinoma of the lung is admitted to the hospital to undergo chemotherapy. Six days after treatment is started, she develops a temperature of 38°C (100.4°F). Physical examination shows no ot her abnormalities. 3 Laboratory studies show a leukocyte count of 100/mm (5% segmented neutrophils and 95% lymphocytes). Which of the following is the most appropriate pharmacotherapy to increase this patient's leukocyte count? Darbepoetin (A) (B) Dexameth asone (C) Filgrastim (D) Interferon alfa - (E) Interleukin - 2 (IL 2) (F) Leucovorin A 37 - year - 8. old woman with right lower extremity edema is evaluated because of the sudden onset of shortness of breath and pleuritic chest pain. A diagnosis of pulmonary embolism is made. Which of the following signs, if present on physical examination, would be the most specific indicator of pulmonary arterial hypertension in this patient? (A) Increased jugular venous pressure (B) P louder than A 2 2 (C) Peripheral edema ( D) Presence of an S 3 (E) Pulmonary crackles 9

11 9. During an experiment, a Southern blot analysis is done by digesting DNA samples with a single restriction endonuclease, separating the digestion products by gel electrophoresis, and transferring them to a filter. The investigator probes the filter by - constant region. The figure shows the resulting pattern exposing it to a cDNA clone that encodes a single immunoglobulin the Southern blot analysis results with DNA samples isolated from different organs. Assuming there were no technical errors, demonstrate which of the following processes? (A) Affinity maturation (B) Apoptosis (C) Gene rearrangement (D) RNA splicing (E) Somatic hypermutation During a clinical study examining the effects of exercise, men 10. - years are evaluated during a 15 between the ages of 20 and 30 minute session on a treadmill. The average pulse for the last 2 minutes of the session is 175/min. During the last minute of nt before the session, which of the following is exercise, various measurements are taken. Compared with the measureme most likely to be decreased? (A) Cardiac output (B) Oxygen consumption (C) Pulse pressure (D) Stroke volume (E) Systolic blood pressure (F) Total peripheral resistance 10

12 11. A 26 year - old man is brought to the emergency department by ambulance 30 minutes after being shot in the leg. He is - mm Hg. unconscious and appears markedly pale. His pulse is 120/min, respirations are 16/min, and blood pressure is 80/60 Compared with a healthy adult, which of the followi ng findings is most likely in this patient? Arterial Baroreceptor Systemic Vascular Pulmonary Vascular Systemic Capillary Resistance Resistance Firing Rate Fluid Transfer ↑ ↑ ↑ filtration (A) ↑ ↓ (B) ↑ absorption (C) ↓ ↓ filtration ↑ (D) ↓ ↑ ↑ absorption (E) ↓ ↑ ↓ filtration ↓ (F) ↓ ↓ absorption minutes after being found with a "blank stare" and flat facial 12. A 17 - year - old boy is brought to the emergency department 30 mm expression at a party. His pulse is 72/min, and blood pressure is 104/68 Hg. He is sitting upright and appears catatonic. Physical examination shows rigidity. During the examination, he becomes hostile and attempts to assault the physician. This patient most likely ingested which of the following drugs? (A) Cocaine ( B) Diazepam (C) Methamphetamine (D) Oxycodone (E) PCP (phencyclidine) - 13. - year - old woman is brought to the emergency department because of an 8 A 26 hour history of severe back and abdominal pain and mild but persistent vaginal bleeding. Ultrasonography of t he abdomen shows a 2 - cm ectopic pregnancy in the ampulla. The ampulla has ruptured into the surrounding tissue. Fluid from this rupture will most likely be found in which of the following locations? (A) Lesser peritoneal cavity (B) Mesometrium (C) of Douglas Pouch (D) Uterine cavity (E) Vagina A 14 - year - old girl has had nausea, intermittent diarrhea, and a 2.2 - kg (5 - lb) weight loss over the past 4 weeks. Examination 14. 3 shows a migrating serpiginous pruritic perianal rash. Her leukocyte count is 8000/mm wi th 20% eosinophils. Which of the following tests is most likely to yield an accurate diagnosis? (A) Blood smear (B) Bone marrow biopsy (C) KOH preparation (D) Microscopic examination of the stool Skin snip (E) 11

13 15. year - old woman comes to the physician because of a 6 - month history of increased facial hair growth. Her last menstrual A 40 - 2 . Her pulse is 80/min, and period was 4 months ago. She is 165 cm (5 ft 5 in) tall and weighs 70 kg (154 lb); BMI is 26 kg/m blood pressure is 130/82 mm Hg. Physical examinat ion shows temporal balding and coarse dark hair on the upper lip and chin. Pelvic examination shows clitoral enlargement. Her serum testosterone concentration is increased. Serum concentrations of androstenedione, dehydroepiandrosterone, and urinary 17 - ket osteroids are within the reference ranges. - cm ovarian mass. Which of the following best describes this mass? Ultrasonography of the pelvis shows a 12 (A) Granulosa tumor (B) Ovarian carcinoid Sertoli - Leydig tumor (C) Teratoma (D) (E) Thecoma week history of - year - o ld woman with systemic sclerosis (scleroderma) comes to the physician because of a 3 16. A 45 - progressive shortness of breath and nonproductive cough. Her temperature is 36.9°C (98.4°F), pulse is 82/min, respirations are 20/min, and blood pressure i s 136/85 mm Hg. Crackles are heard in both lower lung fields. Pulmonary function tests show total lung capacity is 80% of predicted, and diffusing capacity for carbon monoxide, corrected for alveolar volume, is 65% of predicted. Histologic examination of a lung biopsy specimen is most likely to show which of the following findings? (A) Diffuse interstitial fibrosis (B) Intra - alveolar exudates (C) Multiple thromboemboli (D) Necrotizing vasculitis necrotizing interstitial granulomas (E) Non - test to detect prostate cancer is evaluated in 300 male volunteers. A needle biopsy of the prostate gland is done 17. A new blood - specific antigen concentrations greater than 5 on all men with serum prostate (N<4). One hundred men undergo ng/mL biopsy procedures; 90 are f ound to have prostate cancer, and five are found to have chronic prostatitis. Which of the following is necessary to calculate the sensitivity of this test? (A) Incidence of chronic prostatitis in the general population (B) Number of men with test results greater than 5 ng/mL and a normal biopsy specimen (C) Prevalence of chronic prostatitis in the general population (D) Prostate biopsies of men with test results equal to or below 5 ng/mL year 18. A 62 - n for 1 - old woman comes to the physician because of low back pai week. Menopause occurred 10 years ago. Physical examination shows localized tenderness over the lumbar spine after movement. X - rays of the spine show a - 2. A DEXA scan shows decreased bone mineral density. Serum calcium an compression fracture of L1 d phosphorus concentrations and serum alkaline phosphatase activity are within the reference ranges. A bisphosphonate drug is prescribed. The expected beneficial effect of this drug is most likely due to which of the following actions? (A) Decreased insul in - like growth factor - 1 concentration (B) Decreased osteoclast activity (C) Decreased osteoprotegerin production (D) Increased 1,25 - dihydroxycholecalciferol concentration (E) Increased osteoblast activity ANKL) production (F) Increased receptor activator of NF - κB ligand (R 12

14 tablets of aspirin in a 19. - old woman is brought to the emergency department 3 hours after ingesting approximately 50 year A 26 - pressure is suicide attempt. She is nauseated, confused, and sleepy. Her pulse is 130/min, respirations are 30/min, and blood mm Hg. Which of the following sets of laboratory values is most likely on evaluation of blood obtained before 100/60 treatment? Serum Arterial Blood − HCO pH P CO 2 3 ↑ (A) ↑ ↓ ↓ ↓ ↓ (B) ↑ (C) ↑ ↓ (D) ↓ ↑ ↓ ↑ (E) ↑ ↑ 20. An investigator is studying the incidence of the common cold among medical students at various time points during the school year. Results show an increased incidence of upper respiratory tract infections among these students during finals week. It is hypothesized that th e stress of studying for examinations adversely affects the immune system, making the students more susceptible to infection. Which of the following laboratory findings in these students during examination week is most likely to support this hypothesis? ( A) AM serum cortisol concentration Decreased (B) Decreased macrophage activity (C) Increased basophil count (D) Increased lymphocyte count (E) Increased natural killer cell activity 21. - year - old man is brought to the emergency department because of a 4 - day history of increasingly severe left leg pain and A 63 - month history of increasingly severe upper midthoracic back pain. During this time, swelling of his left calf. He also has a 1 - kg (20 - lb) weight loss despite no change in appetite. He has no history of major medical illness. His only he has had a 9 2 cm (5 ft 11 in) tall and weighs 82 kg (180 lb); BMI is 25 kg/m medication is ibuprofen. He is 180 . His vital signs are within normal limits. On examination, lower extremity pulses are palpable bilaterally. The remainder of the physical examination shows no abnormalities. An x - ray of the thoracic spine shows no abnormalities. A CT scan of the abdomen shows a 3 - cm mass in the body of the pancreas; there are liver metastases and encasement of the superior mesenter ic artery. Ultrasonography of the left lower extremity shows a femoropopliteal venous clot. Which of the following is the most likely cause of this patient’s symptoms? (A) Carcinoid syndrome (B) Hypercoagulability from advanced malignancy ocrine neoplasia (C) Multiple end (D) Splenic artery aneurysm and embolic disease of the left lower extremity Superior mesenteric artery syndrome (E) 22. A 35 year - old man comes to the physician because of pain and swelling of his right arm where he scraped it on a tree bran ch - 2 days ago. His temperature is 38.3°C (101°F). Examination of the right forearm shows edema around a fluctuant erythematous lesion at the site of trauma. The area is extremely tender to palpation. Which of the following is most likely t he primary mechan ism of the development of edema in this patient? (A) Degranulation of eosinophils (B) Disruption of vascular basement membranes (C) Increased hydrostatic pressure (D) Release of thromboxane Separation of endothelial junctions (E) 13

15 - year - old boy from Brazil is brought to the physician because of a 1 - week history of painless swelling of his jaw and 23. A 4 percentile for height and weight. Physical examination shows a single 12 × pressure around his eyes. He is at the 80th - cm 10 lesion in the right side of the jaw with diffuse limits and irregular edges. Photomicrographs of an incisional biopsy specimen of the lesion are shown. Based on these findings, which of the following processes is most likely occurring in the region indicated by the arrows? (A) Apop tosis (B) Necrosis (C) Oncosis Ostosis (D) Symptosis (E) 24. A 33 - year - old woman comes to the physician because of a 2 - day history of mild nausea, increased urinary urgency and frequency, and constipation. She also has had a 4.5 kg (10 - lb) weight loss during the past 2 - weeks and a 3 - week history of vaginal bleeding. Pelvic examination shows a nodular cervix with an irregular, friable posterior lip, and a rock - hard, cimens from the cervix and anterior irregular, immobile pelvic mass that extends across the pelvis. Examination of biopsy spe wall of the vagina show well differentiated keratinizing squamous cell carcinoma. Which of the following best describes the - pathogenesis of this patient's disease? (A) Inactivation of cellular p53 (B) Insertion of viral promotors adjacent to cellular growth factor genes (C) Specialized transduction (D) Transactivation of cellular growth factor genes by TAX (E) Translocation of CMYC to an Ig gene promoter A 27 25. year - - old man is admitted to the hospital 45 minutes after be ing involved in a motor vehicle collision. Physical examination shows a sluggish response to stimuli. Neurologic examination shows no other abnormalities. A skull x ray - shows a linear, nondepressed basal skull fracture. Two weeks later, the patient develop s polyuria and polydipsia. Laboratory studies show a serum glucose concentration within the reference range, increased serum osmolality, and decreased urine osmolality. Following the administration of desmopressin, urine osmolality increases. The beneficia l effect of this drug is most likely due to activation of which of the following? (A) Adenylyl cyclase 2+ Ca (B) channels (C) Janus kinase (D) Serine kinase (E) Tyrosine kinase 14

16 6 A 30 year - - - week history of colicky abdominal pain and diarrhea 26. old man is admitted to the hospital for evaluation. He has a with occasional blood. Three days after admission, he suddenly develops peritonitis and sepsis. Despite appropriate care, he nd serosal surfaces, and a punctate opening is dies. At autopsy, examination shows a fibrinous exudate over the peritoneal a and seen in the wall of a thickened loop of small intestine. Several lengths of the small and large intestines are also thickened adherent to one another, with marked areas of narrowing. Photomicrographs of a section of the colon are shown. Which of the following is the most likely diagnosis? (A) Colon cancer (B) Crohn disease (C) Diverticulitis (D) Ischemic necrosis (E) Ulcerative colitis 27. A couple comes for preconceptional genetic counseling because they both have a family history of α - thalassemia. The woman has a minimally decreased hemoglobin concentration. Genetic studies show a single gene deletion. The man has (one deletion on the maternal gene and one microcytic anemia and a t wo - gene deletion. If the two - gene deletion is in trans deletion on the paternal gene), which of the following percentages of their offspring will have a two - gene deletion? 0% (A) (B) 25% (C) 50% (D) 75% (E) 100% year 28. A healthy 22 - - old man participates in a study of glucose metabolism. At the beginning of the study, his serum glucose concentration is within the reference range. He consumes an 800 calorie meal consisting of protein, fat, and carbohydrates. - He then sleeps through the night without additional food or drink. Twelve hours later, his serum glucose concentration remains within the reference range. Which of the following mechanisms is most likely involved in maintaining this man's serum glucose concentrati on? (A) Continued gut absorption of calories from the ingested meal (B) Glucose release from skeletal muscle (C) Glycogenolysis in the liver (D) Increased leptin release from adipose tissues (E) Inhibition of glucagon release by the pancreas 15

17 hour after police found him unresponsive. His yea r - old homeless man is brought to the emergency department 1 - 29. A 63 ing respirations are 30/min. Crackles are heard over the left upper and the entire right lung fields. Despite appropriate lifesav measures, he dies. A photomicrograph of a section of the right lung obtained at autopsy is shown. Which of the following mediators is the most likely cause of the position of the cell indicated by the arrow? (A) Bradykinin C5a (B) (C) Histamine (D) Nitrous oxide (E) Prostagla ndins 30. A 16 - year - old boy is brought to the physician because of a 3 - day history of abdominal pain and vomiting; he also has had decreased appetite during this period. The pain was initially on the right but now has become generalized. His temperature (101.8°F), pulse is 100/min, respirations are 20/min, and blood pressure is 143/83 38.8°C is mm Hg. Abdominal examination shows guarding with diffuse rebound tenderness. There are no palpable masses. A CT scan of the abdomen shows a nation of peritoneal fluid from this patient will most likely show which of the following perforated appendix. Exami organisms? Candida albicans (A) (B) Citrobacter freundii (C) Escherichia coli (D) Staphylococcus aureus (E) Streptococcus pneumoniae old boy is admitted 31. A 16 - year - - to the emergency department because of a knife wound to the left side of his chest. An x ray of the chest shows an air - fluid level in the left side of the chest, partial collapse of the left lung, and elevation of the stomach the midline. Which of the following is the most likely diagnosis? bubble. The mediastinum is in (A) Hemopneumothorax, not under tension (B) Hemothorax, not under tension (C) Pneumothorax, not under tension (D) Tension hemopneumothorax (E) Tension hemothorax Tension pneumothorax (F) 16

18 32. year - old woman comes to the physician because of a 5 - year history of heavy bleeding with menses that often requires A 20 - - her to change her sanitary pads three times hourly. Menses occur at regular 28 day intervals. She recently sustained a minor cut to he r finger, and the bleeding took longer to stop than usual. She has not had easy bruising or change in weight. She only takes an oral contraceptive, but she has not been sexually active for the past 6 months. Her temperature is 37.5°C (99.5°F), min, respirations are 12/min, and blood pressure is 120/66 mm Hg. Physical examination shows mildly pale pulse is 72/ conjunctivae. Pelvic examination shows no abnormalities. Laboratory studies show: 10.5 g/dL Hemoglobin 31.3% Hematocrit concentration 28% Hb/cell Mean corpuscular hemoglobin 3 70 μm Mean corpuscular volume 3 5500/mm Leukocyte count 3 Platelet count 275,000/mm Platelet aggregation studies normal 10.5 sec (INR=1.0) Prothrombin time Partial thromboplastin time 28 sec A Pap smear shows no abnormalities. Which of the following hematologic disorders is the most likely cause of this patient's menorrhagia? (A) Afibrinogenemia (B) Hemophilia A (C) Intravascular coagulation (D) Vitamin K deficiency (E) von Willebrand disease is brought to the physician for a well 33. A 2 - year - old boy child examination. He was delivered at term after an uncomplicated - 5 pregnancy. His birth weight was 3500 (7 lb 11 oz), and Apgar scores were 8 and 10 at 1 and minutes, respectively. At the g months, physic al examination showed no abnormalities, but he was not yet talking. Both of his parents had learning age of 15 difficulties in school, and his mother stopped attending after the 10th grade. He has a maternal uncle with cognitive perce ntile for height, 15th percentile for weight, and 90th percentile for head circumference. He disabilities. He is at the 25th appears irritable, he resists making eye contact, and he is flapping his hands. Which of the following is the most likely cau se of this patient's condition? C reation of an alternative splice site (A) (B) Frameshift mutation (C) Missense mutation (D) Nonsense mutation (E) Trinucleotide repeat expansion A 31 - year - old woman with type 2 diabetes mellitus comes to the physician because of an oozing, foul - 34. wound on her smelling foot for 2 days. Physical examination shows a 4 - cm, necrotizing wound with a purplish black discoloration over the heel. Crepitant bullae producing profuse amounts of serous drainage are seen. A Gram stain of a tissue biopsy specimen shows gra m - positive rods. The causal organism most likely produces which of the following virulence factors? Endotoxin (A) (B) Fimbriae (C) Pneumolysin (D) Polysaccharide capsule - (E) α Toxin 17

19 35. month - old boy is brought to the physician because of a 4 - day histo ry of fever and cough. His illness began with low - A 10 - grade fever and copious, clear nasal discharge. Two days ago he developed a moist, nonproductive cough and rapid - care center and has three school - breathing. He has received all scheduled childhood immunizations. He attends a large day aged siblings. His temperature is 38°C (100.4°F), pulse is 101/min, respirations are 38/min, and blood pressure is mm Hg. Physical examination shows nasal flaring and rhinorrhea. Chest examination shows intercostal retrac tions 85/60 s along with bilateral, diffuse wheezes and expiratory rhonchi. The infectious agent of this patient's condition most likely ha which of the following properties? (A) DNA genome Double - stranded nucleic acid genome (B) Mature virion lacking viral polymerase (C) (D) Mediation of cell entry via a fusion protein (E) Viability on surfaces for several weeks A 17 - year - old girl is brought to the emergency department 15 36. minutes after being stung by a bee. She has mild light - headedness but no difficulty swall owing. Her temperature is 37.1°C (98.8°F), pulse is 100/min, respirations are 30/min, and blood pressure is 115/70 mm Hg. Physical examination shows no urticaria. Bilateral wheezing is heard on auscultation of the chest. Which of the following types of dru gs is the most appropriate pharmacotherapy for this patient? (A) α - Adrenergic agonist 1 (B) α - Adrenergic agonist 2 (C) α - Adrenergic antagonist 1 (D) Adrenergic agonist β - 2 (E) β - Adrenergic antagonist 2 A 30 - year - 37. 28 weeks' gestation comes to the office for a prenatal visit. She has had old woman, gravida 2, para 0, aborta 1, at one previous pregnancy resulting in a spontaneous abortion at 12 weeks' gestation. Today, her vital signs are within normal limits. Physical examination shows a uterus consistent in size with a 28 - week gestation. Fetal ultrasonography shows a male fetus with no abnormalities. Her blood group is O, Rh negative. The father's blood group is B, Rh - positive. The physician - recommends administration of Rh (D) immune globulin to the patient. This treatment is most likely to prevent which of the o following in this mother? (A) Development of natural killer cells (B) Development of polycythemia (C) Formation of antibodies to RhD (D) Generation of IgM antibodies from fixing complement in the fetus (E) Immunosuppression caused by RhD on erythrocytes from the fetus A 52 38. year - old woman begins pharmacotherapy after being diagnosed with type 2 diabetes mellitus. Four weeks later, her - hepatic glucose output is decreased, and target tissue glucose uptak e and utilization are increased. Which of the following drugs was most likely prescribed for this patient? (A) Acarbose (B) Glyburide (C) Metformin (D) Nateglinide (E) Repaglinide 18

20 39. - year - old man with multiple sex partners has dysuria and a yellow urethral exudate. Gram stain of the A sexually active 23 - exudate shows numerous neutrophils, many that contain intracellular gram negative diplococci. He has had three similar of the infecting organism best explains the episodes of urethritis over the past 2 years. Which of the following properties reinfection? (A) Antigenic variation (B) Catalase (C) Inhibition of B - lymphocyte function (D) Inhibition of T - lymphocyte function (E) Polysaccharide capsule old girl is brought to the physician by 40. A 17 - year - her mother because she has not had a menstrual period for 6 months. The patient is unconcerned about the lack of menses. Menarche occurred at the age of 12 years, and menses had occurred at regular 28 - day intervals until they became irregular 1 year ago. S he is a member of her high school gymnastics team. She 2 cm (5 ft 4 in) tall and weighs 40 kg (88 lb); BMI is 15 kg/m appears emaciated. She is 163 . Her pulse is 54/min, and blood mm Hg. Which of the following is the most likely cause of t pressure is 80/50 his patient's amenorrhea? Hyperthyroidism (A) (B) Hypogonadotropic hypogonadism (C) Hypothyroidism (D) Polycystic ovarian syndrome (E) Prolactinoma 19

21 USMLE STEP 1 SAMPLE TEST QUESTIONS - BLOCK 2, ITEMS 41 80 A 49 41. year - old woman comes to the physician fo r a follow - up examination. She has a strong family history of coronary artery - mm Hg to 130/85 mm Hg during the previous three visits within the past disease. Her blood pressure has ranged from 150/95 mm Hg. Phys ical examination shows no other abnormalities. Laboratory months. Her blood pressure today is 140/90 2 studies show: Cholesterol, total 290 mg/dL cholesterol HDL - 40 mg/dL LDL cholesterol 190 mg/dL - Triglycerides 350 mg/dL Treatment with atorvastatin and losartan is initiated. Which of the following serum findings is most likely to occur in this patient? HDL - cholesterol Triglycerides (A) Decreased decreased (B) Decreased increased (C) Increased decreased (D) Increased increased No change (E) no change - year - old girl comes to the physician because of a 3 - month history of acne. Breast and pubic hair development began at 42. A 15 the age of 12 years. Physical examination shows scattered open and closed years. Menarche occurred at the age of 14 comedones over the cheeks and forehead. Breas t and pubic hair development are Tanner stage 5. Which of the following is the most likely underlying cause of this patient's acne? (A) Decreased parasympathetic stimulation to the sebaceous glands (B) Increased estrogen stimulation of the sebaceous gland s (C) Increased responsiveness of the sebaceous glands to follicle - stimulating hormone (D) Increased sympathetic stimulation to the sebaceous glands (E) Stimulation of the sebaceous glands by androgens he emergency department because of constant substernal chest pain for 43. year - old man is brought to t - A previously healthy 40 hours that is exacerbated by coughing and inspiration. The pain is relieved with sitting up and leaning forward. There is no 12 100.4°F), pulse is 120/min, and blood pressure is 110/60 mm Hg. family history of heart disease. His temperature is 38°C ( - segment The lungs are clear to auscultation. Cardiac examination shows distant heart sounds. An ECG shows diffuse ST - st likely cause of his condition is injury to which ray of the chest shows normal findings. The mo elevation in all leads. An x of the following tissues? (A) Aortic intima (B) Esophageal sphincter (C) Myocardium (D) Pericardium (E) Pleura 20

22 44. year - old man is brought to the emergency department because of shortness of breath and confusion for 4 hours. He has A 55 - hypertension and chronic kidney disease requiring hemodialysis. An ECG shows low voltage with electrical alternans. Physical examination is most likely to show which of the following findings? Jugular Blood Pressure Pulsus Venous Pulse (/min) Pressure Paradoxus (mm Hg) 120 increased increased 85/60 (A) 85/60 120 increased normal (B) 85/60 (C) 120 normal normal (D) 80 increased increased 120/80 (E) 120/80 80 normal increased (F) 120/80 80 normal normal 45. A 54 - year - old woman comes to the emergency department because of severe jaw pain since undergoing a painful dental procedure 1 day ago. The patient was prescribed codeine after the procedure and instructed to take the medication every 4 hours, but she has co ntinued pain despite adherence to this analgesic regimen. Other members of her family also have experienced poor pain control with codeine. Which of the following is the most likely explanation for this therapeutic failur e? (A) eine Decreased absorption of cod (B) Decreased metabolism of codeine to morphine Deficiency of κ receptors (C) Increased plasma protein - binding of codeine (D) Increased renal clearance of codeine (E) A 14 - year - - 46. year history of type 1 diabetes mellitus is brought to the physician by her mother for a follow - up old girl with a 9 examination. She has been admitted to the hospital twice in the past 3 months because of diabetic ketoacidosis. She previously had been compliant with monitoring her blood glucose concentration and with her diet and insulin regimen. She acknowledges that, when she is with her peers, she eats whatever she wants and does not check her blood glucose difficulty concentration. She adds, "I'm embarrassed to inject myself in front of them." The physician is having a great deal of with her 15 year - old son who has been truant from school and sneaking out of the house. She says to the patient, "You should - be ashamed for not taking care of yourself. We've all worked so hard to keep you healthy." Which of the following terms best describes the physician's reaction to the patient? (A) Countertransference (B) Identification with the aggressor (C) Projection Splitting (D) Sublimation (E) 47. A 23 - year - old woman with bone marrow failure is treated with a large dose of rabbit antith ymocyte globulin. Ten days later, she develops fever, lymphadenopathy, arthralgias, and erythema on her hands and feet. Which of the following is the most likely cause of these symptoms? (A) Cytokine secretion by natural killer cells (B) Eosinophil degran ulation (C) Immune complex deposition in tissues (D) Polyclonal T - lymphocyte activation (E) Widespread apoptosis of B lymphocytes 21

23 48. year - old man is brought to the emergency department because of a 6 - day history of fever, severe muscle pain, and A 25 - e, painful swelling of his neck, underarms, and groin area. The symptoms began after returning from a camping trip in diffus New Mexico. He appears ill and lethargic and can barely answer questions. His temperature is 39.2°C (102.5°F), pulse is mm 120/min, respirati ons are 22/min, and blood pressure is 110/70 Hg. Physical examination shows generalized scattered black maculae. Examination of the right upper extremity shows an erythematous, solid, tender mass on the underside of the upper extremity just above the el bow; the mass is draining blood and necrotic material. The most effective antibiotic for this patient’s disorder will interfere with which of the following cellular processes or enzymes? Cell wall synthesis (A) (B) DNA helicase Glucuronosyltransferase (C) Proteasomal degradation (D) Ribosomal assembly (E) Tetrahydrofolate reductase (F) - A 42 - year 49. old woman comes to the physician because of anxiety, tremor, and a 5 - kg (11 - lb) weight loss over the past 4 months despite good appetite. Physical examination shows fine thin hair, exophthalmos, goiter, and warm moist skin. Cardiac examination shows tachycardia and a widened pulse pressure. Which of the following sets of laboratory values is most likely in this patient's serum? Thyroid - stimulating Total Thyro xine Free Thyroid - binding (T Hormone ) Thyroxine Globulin 4 ↑ (A) ↑ ↑ ↑ (B) ↑ ↑ normal ↓ (C) ↓ ↑ normal ↑ (D) ↑ ↑ normal ↓ normal normal ↑ (E) ↓ ↓ normal normal (F) normal 50. A 29 - year - old woman is prescribed carbamazepine for trigeminal neuralgia. She has a strong family history of osteoporosis. As a result, the physician also advises her to increase her intake of vitamin D. The most likely reason for this tic processes? recommendation is that carbamazepine may affect which of the following pharmacokine (A) Absorption (B) Distribution (C) Excretion (D) Metabolism (E) Protein binding Over 1 year, a study is conducted to assess the antileukemic activity of a new tyrosine kinase inhibitor in patients with 51. chronic myeloid leukemia in blast c risis. All patients enrolled in the study are informed that they would be treated with the tyrosine kinase inhibitor. They are assigned to successive dose cohorts of 300 to 1000 mg/day of the drug. Six to eight patients are assigned to each dose. Treatment efficacy is determined based on the results of complete blood counts and bone marrow assessments conducted regularly throughout the study. This study is best described as which of the following? (A) Case - control study (B) Crossover study (C) Open - labeled clinical trial (D) Randomized clinical trial blind, randomized, controlled trial (E) Single - 22

24 52. year - old man with non - Hodgkin lymphoma comes to the physician because of a 3 - week history of progressive A 64 - legs when he stands. He received his third course of chemotherapy numbness in his hands and feet and weakness in his 4 weeks ago. Physical examination shows areflexia. Which of the following drugs is the most likely cause of these adverse effects? Bleomycin (A) Cyclophosphamide (B) (C) Cytarabine Dox orubicin (D) Fluorouracil (E) (F) Methotrexate (G) Vincristine 53. During an experiment, drug X is added to a muscle bath containing a strip of guinea pig intestinal smooth muscle. Agonists are added to the bath, and the resultant effects on muscle tension are shown in the table. Muscle Tension Before Drug X (g) Muscle Tension After Drug X (g) Agonist Vehicle 6.0 6.1 Acetylcholine 11.3 18.5 Norepinephrine 4.1 4.2 Which of the following types of drugs is most likely to produce effects most similar to those of drug X? (A) α Adrenergic antagonist - 1 - Adrenergic antagonist (B) β (C) Cholinesterase inhibitor Monoamine oxidase inhibitor (D) Muscarinic antagonist (E) 54. A 42 - year - old man comes to the physician for a follow - up examination. Four months ago, he underwent repair of a Dupuytren contracture. Physical examination shows decreased range of motion in the affected hand. The patient is upset that s the most likely his hand has not fully healed, and he files a malpractice suit against the physician. Which of the following i precipitating factor in this patient's decision to file a malpractice suit? (A) The patient's perception that the physician is incompetent (B) The patient's perception that the physician is uncaring (C) The patient's socioeconomic status The physician's amount of experience in the medical field (D) (E) The physician's inability to screen out problem patients A 72 - year - old woman comes to the physician because of a 2 - 55. month history of painless swelling of both ankles. She also reports shor tness of breath with exertion and when lying down. She has been awakened from sleep by shortness of breath. She has not had chest pain. Her pulse is 96/min and regular, respirations are 24/min, and blood pressure is 128/76 mm Hg. Jugular venous pressure is 15 cm H O. Pulmonary examination shows crackles at both lung bases. Cardiac examination 2 shows a regular rhythm and a soft S . A grade 3/6 holosystolic murmur is heard best at the apex, radiating to the axilla. There 3 nd ankles. Which of the following is most likely to confirm the diagnosis? is 2+ pitting edema of the lower legs a (A) Measurement of serum troponin I concentration (B) ECG (C) Exercise stress test (D) Echocardiography (E) Pulmonary artery catheterization 23

25 56. year - old boy is brought to the p hysician for a physical examination prior to participating in sports. He appears reluctant A 14 - to remove his shirt for the examination, and says that he is embarrassed because he has grown breasts during the past year. nd weight. Physical examination shows bilateral 1.5 - He is at the 50th cm fibroglandular masses located percentile for height a areolar complex and normal penis and testes. Pubic hair development is Tanner stage 3. - Serum beneath the nipple concentrations of gonadotropic hormones, estrogens, and tes tosterone are within the reference ranges. Which of the following is the most likely cause of this patient's breast enlargement? Breast adenocarcinoma (A) (B) Estradiol - secreting Leydig cell tumor Peutz - Jeghers syndrome (C) Seminiferous tubule dysgene sis (Klinefelter syndrome) (D) (E) Normal development - year - old boy is admitted to the hospital because of a 1 - week history of fever and increasingly severe abdominal 57. A 5 discomfort. At the age of 7 months, he was treated for osteomyelitis caused by Aspergillus fumigatus . He has been admitted to the hospital three times during the past 4 years for severe pneumonia. He appears moderately ill. His temperature is 39°C (102.2°F). Abdominal examination shows an enlarged, tender liver. Ultrasonography of th e abdomen shows an intrahepatic abscess. Culture of the abscess fluid grows . Further analysis shows failure of the Staphylococcus aureus neutrophils to undergo an oxidative burst when exposed to S. aureus . This patient has an increased susceptibility to in fection as a result of which of the following abnormalities? (A) Deficient leukocyte production (B) Failure of leukocytes to migrate between endothelial cells (C) Failure of leukocytes to roll along the endothelial surface Inability of leukocytes to i (D) ngest microorganisms (E) Inability of leukocytes to kill intracellular microorganisms 58. - year - old woman contacts a medical student and asks if he would like to join her for dinner. The student met the woman A 22 week hospitalization for treatment of major depressive disorder. He has not when he was assigned to her care during her 2 - treated or seen the patient since she was discharged from the hospital. He is attracted to this former patient and would be interested in dating her. Which of the following is the most appropriate action by the medical student regarding this patient's invitation? (A) He can date her because he was a medical student, not a physician, when he contributed to her care (B) He can date her because she is no longer his patient He can (C) date her, but only after at least 1 year has passed since he treated her (D) He cannot date her because she was once his psychiatric patient (E) He cannot date her unless she agrees never to seek care at his hospital in the future 59. A 73 - year - old woman comes to the physician because of a 2 - month history of diffuse weakness and tingling of her arms and legs. Neurologic examination shows weakness of the extensor and flexor muscles of the lower extremities. Knee and ankle deep tendon reflexes are exaggerate d. Sensation to vibration and position is decreased in all extremities, but the decrease is more prominent in the lower extremities than in the upper extremities. This patient most likely has a deficiency of which of the following vitamins? (A) Niacin (B) Vitamin B (thiamine) 1 Vitamin B (C) (riboflavin) 2 (D) Vitamin B (pyridoxine) 6 (cyanocobalamin) (E) Vitamin B 12 24

26 60. year - old man comes to the physician because of right shoulder pain that began after he chopped wood 2 days ago. A 45 - Examination of the right upper extremity shows no obvious bone deformities or point tenderness. The pain is reproduced when the patient is asked to externally rotate the shoulder against resistance; there is no weakness. In addition to the tere s minor, inflammation of which of th e following tendons is most likely in this patient? Infraspinatus (A) Pectoralis (B) (C) Subscapularis Supraspinatus (D) Trapezius (E) old man comes to the physician for a follow A 54 - year - - 61. up examination 10 days after undergoing a stereotactic brain ope ration to remove a small tumor. The operation was successful. During the procedure, he was under conscious sedation. The patient recalls that at one point during the operation he experienced a sudden, intense feeling of overwhelming fear. Which of the foll owing areas of the brain was most likely stimulated at that time? Amygdala (A) Hippocampus (B) (C) Mammillary body (D) Prefrontal cortex (E) Thalamus 62. A placebo - controlled clinical trial is conducted to assess whether a new antihypertensive drug is more effective than standard therapy. A total of 5000 patients with essential hypertension are enrolled and randomly assigned to one of two groups: 2500 patients receive the new drug and 2500 patients receive placebo. If the alpha is set at 0.01 instead of 0.05 , which of the following is the most likely result? (A) Significant findings can be reported with greater confidence The study will have more power (B) (C) There is a decreased likelihood of a Type II error statistically significant findings (D) There is an increased likelihood of (E) There is an increased likelihood of a Type I error 63. A male stillborn is delivered at 32 weeks' gestation to a 30 - year - old woman. The pregnancy was complicated by oligohydramnios. Examination of the stillborn shows the absence of a urethral opening. Which of the following additional findings is most likely in this stillborn? (A) Congenital diaphragmatic hernia (B) Intralobar sequestration (C) Pulmonary hypoplasia (D) Situs inversus (E) Tracheoesophageal fistula 33 - year - old man undergoes a radical thyroidectomy for thyroid cancer. During the operation, moderate hemorrhaging 64. A requires ligation of several vessels in the left side of the neck. Postoperatively, serum studies show a calcium concentratio n of 7.5 mg/dL, a lbumin concentration of 4 g/dL, and parathyroid hormone concentration of 200 pg/mL. Damage to which of the following vessels caused the findings in this patient? (A) Branch of the costocervical trunk (B) Branch of the external carotid artery (C) Branch of the thyrocervical trunk (D) Tributary of the internal jugular vein (E) Tributary of the left brachiocephalic vein (F) Tributary of the right brachiocephalic vein 25

27 A 42 65. year - old man comes to the physician for a follow - up examination 1 week after he passed a renal calculus. X - ray - crystallographic analysis of the calculus showed calcium as the primary cation. Physical examination today shows no - abnormalities. A 24 hour collection of urine shows increased calcium excretion. Which of the following is the most appropriate pharmacotherapy? (A) Carbonic anhydrase inhibitor + − Cl Na symport inhibitor (B) – + + − – – K (C) 2Cl Na symport inhibitor (D) Osmotic diuretic (E) Renal epithelial sodium channel inhibitor 66. A 55 - year - old man comes to the physician because of a 2 - week history of recurrent, widespread blister formation. Physical examination shows lesions that are most numerous in the flexural areas including the axillae and groin. The blisters do not ikely the result of adhesion failure involving which of the break easily, and there are no oral lesions. These blisters are most l following? (A) Basement membrane (B) Dermal papillae (C) Langerhans cells (D) Melanocytes (E) Merkel cells A 24 - year - old man is brought to the emergency department 40 minutes after he was invol ved in a motor vehicle collision. He 67. was the unrestrained driver. He is conscious. Physical examination shows numerous lacerations and ecchymoses over the face. His vision is normal. Ocular, facial, and lingual movements are intact. The gag reflex is prese nt. Sensation to pinprick is absent over the right side of the face anterior to the right ear, extending down along the full extent of the mandible to the chin. Sensation also is absent over the right side of the tongue. X rays of the skull show fractures of the orbit, zygomatic arch, - and infratemporal fossa. The most likely cause of these findings is a fracture affecting which of the following locations? (A) Foramen lacerum (B) Foramen ovale (C) Foramen rotundum Foramen spinosum (D) (E) Jugular foramen 68. A 55 - year - old man who is a business executive is admitted to the hospital for evaluation of abdominal pain. He is polite to the physician but berates the nurses and other staff. The patient's wife and two of his three adult children arrive for a vis it. The patient says with disgust that the missing child is and always has been worthless. Which of the following is the most likely explanation for this patient's behavior? Countertransference (A) (B) Projection (C) Projective identification (D) Reaction formation (E) Splitting 6 2

28 69. - year - old boy with chronic granulomatous disease is brought to the physician because of a 3 - week history of fever and A 3 3 cm, warm, red lumps under both arms. His temperature is 38°C (100.4°F). Physical examination shows enlarged, - erythematous axillary lymph nodes bilaterally. On palpation, the nodes are tender, fluctuant, and movable. Examination of a - positive cocci in clusters. Cultures of the aspirate grow yellow, β - fine - needle aspirate from one of the nodes shows gram lytic colonies that are catalase and coagulase positive. A polymerase chain reaction test shows mecA - positive hemo organisms. Which of the following is the most appropriate pharmacotherapy for this patient? Cefazolin (A) (B) Ciprofloxacin (C) Penicillin G (D) Rifampin (E) Vancomycin An otherwise healthy 45 - year - old man comes to the physician because of a 3 - week history of progressive epigastric heartburn 70. - kg (10 - lb) weight loss. The pain tends to be more severe at night and occurs 1 to 3 hours after meals during the day. and a 4.5 He has had similar episodes with lesser intensity during the past year. Abdominal examination shows tenderness to deep palpation. Test of the stool for occult blood is positive. Endoscopy shows a bleeding 3 - cm ulcer in the antru m of the stomach. A photomicrograph of Steiner silver stained tissue (400x) from a biopsy of the gastric mucosa adjacent to the ulcer is shown. - Which of the following processes is most likely to be involved? (A) Elaboration of proteases and urease with lo cal tissue destruction (B) Hyperacidity and gastric ulcer development (C) Ingestion of preformed toxins in contaminated well water Spirochete invasion of gastric cells (D) 27

29 71. year - old girl is brought to the office by her mother because her school nur se thinks that she may have Marfan A 10 - percentile for height and 25th percentile for weight. Physical examination shows a narrow palate syndrome. She is at the 95th sh with dental crowding, long slender extremities, and joint laxity. Molecular testing for FBN1 ows a single nucleotide cm (5 ft 4 in) tall. There is no clinical difference that does not change the amino acid at that locus. Her mother is 163 evidence of Marfan syndrome in the mother, but she has the same single nucleotide change as the patient. The s ame individuals without Marfan syndrome. Which of the following best describes the nucleotide change is found in 15 of 200 single nucleotide change in the patient and her mother? (A) It is a disease - causing mutation in the patient and her mother It is a polymorphism (B) (C) It is a sequence variant of unknown significance (D) It will change the folding of the protein (E) It will result in a truncated protein A previously healthy 40 - year 72. old woman is brought to the emergency department by her husband beca use of a 2 - day history - of fever, lethargy, and confusion. Her temperature is 38°C (100.4°F), pulse is 80/min, respirations are 18/min, and blood pressure is 140/90 mm Hg. Physical examination shows scattered petechiae and ecchymoses over the lower extremit ies. Neurologic examination shows moderate generalized motor weakness. She is oriented to person but not to place or time. Laboratory studies show: Hemoglobin 9 g/dL Hematocrit 27% 3 Leukocyte count 8000/mm with a normal differential 3 Platelet count 15,000/mm Prothrombin time 12 sec (INR=1.1) Partial thromboplastin time 30 sec Serum Urea nitrogen 25 mg/dL Lactate dehydrogenase 1000 U/L A peripheral blood smear shows 3+ polychromasia and 3+ schistocytes. Urine and blood cultures grow no organisms. A chest x - ray shows no abnormalities. Which of the following is the most likely diagnosis? (A) Acute myeloid leukemia (B) Autoimmune hemolytic anemia (C) Thrombotic thrombocytopenic purpura (D) Toxic shock syndrome (E) von Willebrand disease A 17 - year - old girl has never had a menstrual period. Physical examination shows a normal female body habitus, normal 73. breast development, and normal appearing external genitalia. She has no axillary or pubic hair. The patient refuses to have a pelvic or re ctal examination. Which of the following is the most likely explanation for the clinical presentation? (A) Androgen insensitivity (B) Congenital adrenal hyperplasia (C) Ectodermal dysplasia (D) A psychiatric disorder (E) A sex chromosome mosaicism 28

30 74. 12 - year - old girl is brought to the physician because of a 2 - month history of intermittent yellowing of the eyes and skin. A mg/dL, with a Physical examination shows no abnormalities except for jaundice. Her serum total bilirubin concentration is 3 ponent of 1 mg/dL. Serum studies show a haptoglobin concentration and AST and ALT activities that are within direct com the reference ranges. There is no evidence of injury or exposure to toxins. Which of the following additional findings is mos t likely in this patie nt? Decreased activity of UDP glucuronosyltransferase (A) (B) Gallstones (C) Increased hemolysis (D) Increased serum alkaline phosphatase activity (E) Ineffective erythropoiesis week history of intermittent abdominal pain, A 47 - year - old woman comes to the emergency department because of a 2 75. - nausea, and vomiting. She has had similar episodes sporadically during the past 4 years. Physical examination shows dehydration, jaundice, and upper abdominal distention. Laboratory studies show hyperbilirubin emia. A CT scan and upper gastrointestinal series of the abdomen with oral contrast are shown; the arrows indicate the abnormality. Which of the following is the most likely cause of these findings? (A) Annular pancreas (B) Cirrhosis of the liver (C) Duodenal constriction by the portal vein (D) Duodenal constriction by the superior mesenteric artery (E) Pyloric stenosis 29

31 76. - year - old boy is brought to the office by his mother because of a 3 - day history of fever, sore throat, and itchy eyes. He An 8 st returned from a weeklong summer camp that included hiking trips and swimming lessons in the camp - owned swimming ju pool. He has no history of major medical illness and receives no medications. He appears tired. His temperature is 39.4°C (102.9°F); other vi tal signs are within normal limits. Physical examination shows conjunctival injection and discharge and oropharyngeal erythema. The public health department reports an outbreak of similar symptoms among the other campers and camp volunteers. Which of the f ollowing is the most likely cause of this patient’s symptoms? (A) Adenovirus (B) Cytomegalovirus (C) Epstein - Barr virus (D) Influenza virus (E) West Nile virus 77. A 36 - year - old man with profound intellectual disability is brought to the physician by staff at his facility because of increasing abdominal girth during the past 2 weeks. He is unable to speak, and no medical history is currently available. Physical examination shows a protuberant abdomen with a fluid wave and shifting dullness. There are n o signs of trauma to the area. Laboratory studies show no abnormalities. A CT scan of the abdomen is shown. Fluid is present in which of the following areas as indicated by the arrow? (A) Epiploic foramen (B) Gastrosplenic ligament (C) Hepatorenal pouch (of Morison) (D) Omental bursa (lesser sac) (E) Sulcus pericolicus 30

32 78. A study is designed to evaluate the feasibility of acupuncture in children with chronic headaches. Sixty children with chroni c headaches are recruited for the study. In addition to their usual therapy, all children are treated with acupuncture three times a week for 2 months. Which of the following best describes this study design? Case control - (A) Case series (B) Crossover (C) - sectional (D) Cross Historical cohort (E) (F) Randomize d clinical trial 79. year - old man comes to the emergency department because of a 4 - day history of colicky right flank pain that radiates to A 56 - sided hydronephrosis and a dilated ure ter. the groin and hematuria. Ultrasound examination of the kidneys shows right - Which of the following is most likely to be found on urinalysis? Erythrocyte casts (A) Glucose (B) Leukocyte casts (C) (D) Oval fat bodies Uric acid crystals (E) 80. A 62 - year - old man comes to the physician for a follow - up examination after he was diagnosed with chronic inflammatory interstitial pneumonitis. Following pulmonary function testing, a biopsy specimen of the affected area of the lungs is obtained. Compared with a healthy man, analysis of this patient's biopsy specimen is most likely to s how which of the following patterns of changes in the cell populations of alveoli? Type I Pneumocytes Type II Pneumocytes Fibroblasts ↑ (A) ↑ ↑ (B) ↑ ↑ ↓ (C) ↑ ↓ ↑ (D) ↓ ↓ ↑ (E) ↓ ↑ ↑ (F) ↓ ↑ ↓ (G) ↓ ↓ ↑ (H) ↓ ↓ ↓ 31

33 USMLE STEP 1 SAMPLE TEST QUESTIONS - 117 BLOCK 3, ITEMS 81 81. Six healthy subjects participate in a study of muscle metabolism during which hyperglycemia and hyperinsulinemia is induced. Muscle biopsy specimens obtained from the subjects during the resting state show significantly i ncreased CoA. The increased malonyl - CoA concentration most likely directly inhibits which of the - concentrations of malonyl following processes in these subjects? Fatty acid oxidation (A) Fatty acid synthesis (B) (C) Gluconeogenesis Glycogenolysis (D) Glycolysis (E) Oxidative phosphorylation (F) 82. - year - old woman who has smoked 20 cigarettes daily for the past 38 A 72 years begins using eyedrops for glaucoma. Three days later, she has a marked increase in shortness of breath while walking up a flight of stai rs. Which of the following drugs is the most likely cause of the development of shortness of breath in this patient? (A) Acetazolamide (B) Apraclonidine (C) Epinephrine (D) Latanoprost (E) Timolol months. He also has had difficulty 83. A 54 - year - old man comes to the physician because of epis odes of fainting for 3 years ago. His pulse is 40/min, performing daily tasks because he is easily fatigued. He had a myocardial infarction 12 respirations are 18/min, and blood pressure is 138/85 Hg. Physical examinat ion shows evidence of cannon a waves. An mm - - ECG shows a P wave rate of 40/min, with no apparent relation between the two. Which of the wave rate of 90/min, and an R following is the most likely diagnosis? First - degree atrioventricular block (A) (B) Right bun dle branch block (C) Second - degree atrioventricular block, type I (D) Second - degree atrioventricular block, type II (E) Third - degree atrioventricular block 84. A 15 - year - old boy is brought to the emergency department by his parents because of a 2 - hour history of confusion and agitation. He also has had fever, headache, stiff neck, and vomiting since he returned from summer camp 2 days ago. His parents say he does not use illicit drugs. On arrival, he is combative and there is evidence of hallucinations. His temperature (104°F), pulse is 80/min, respirations are 17/min, and blood pressure is 100/70 mm is 40°C Hg. A lumbar puncture is performed. Results of cerebrospinal fluid analysis show cysts and trophozoites. The most likely portal of pathogen entry in to this patient's central nervous system is which of the following? (A) Cavernous sinus (B) Facial nerve (C) Frontal sinus (D) Mastoid sinus (E) Olfactory nerve Trigeminal nerve (F) 32

34 85. year - old woman comes to the physician for a routine examination. S he says that she has felt well except for occasional A 42 - episodes of constipation, abdominal discomfort, and mild fatigue. She was treated for a renal calculus 10 years ago and was 50/80 mm Hg. Physical examination shows no told she had a "lazy gallbladder." Her pulse is 82/min, and blood pressure is 1 other abnormalities. Laboratory studies show: 3 3 million/mm Erythrocyte count Serum + 4.5 mEq/L K – Cl 107 mEq/L 2+ Ca 12 mg/dL Phosphorus 2.2 mg/dL Alkaline phosphatase 95 U/L The most likely cause of - defined nodule in which of the following locations? this patient's condition is a small, well (A) Adrenal gland (B) Anterior pituitary gland (C) Gallbladder (D) Kidney (E) Parathyroid gland (F) Thymus 86. A new severe respiratory illness caused by a newly identified virus is discovered. Which of the following properties of a killed vaccine relative to a live vaccine is the most appropriate rationale for developing a killed vaccine for this illness? (A) Avoids the concern for reversion to virulence (B) Dev elops more rapid protective immunity (C) Is less likely to require subsequent boosters for lifelong immunity (D) Is most likely to generate mucosal immunity (E) Requires little safety monitoring to ensure inactivation A 72 87. year - old woman comes to the phy sician because of a 3 - day history of fever, shortness of breath, difficulty swallowing, - chest pain, and cough. She is frail. Physical examination shows tachypnea and equal pulses bilaterally. Percussion of the chest shows dullness over the right lower lung field. Laboratory studies show arterial hypoxemia and decreased P CO . A chest 2 - ray shows an area of opacification in the lower region of the right lung. Which of the following is the most likely cause of x this patient's condition? (A) Alveolar proteinosi s (B) Aspiration (C) Cigarette smoking (D) Emphysema (E) Vasculitis A 25 - year - old woman comes to the office because of a 6 - 88. month history of increasingly severe low back pain and heavy menses. Her temperature is 37.1°C (98.8°F), pulse is 75/min, respirati ons are 13/min, and blood pressure is 115/79 mm Hg. Physical examination shows no abnormalities. An endometrial biopsy specimen shows regular tubular endometrial glands with abundant mitotic figures in the endometrial glands and stroma. Which of the follow ing proteins or enzymes regulate the progression of cells into this phase of this patient's menstrual cycle? (A) AMP - dependent kinases (B) Cyclin - dependent kinases (C) Hexokinases (D) Lipid kinases (E) Urokinases 33

35 89. - year - old woman is brought to the emergency department by her husband because of a 1 - hour history of difficulty A 72 walking and speaking. The husband says that she was well last night but when she awoke this morning, she had difficulty getting out of bed and her speech was slurred. She has a 2 - year history of type 2 diabetes mellitus well controlled with 0 medication and diet. She is alert and oriented and is able to follow commands and respond verbally, but she has impaired speech. Her pulse is 80/min, respirations are 16/min, and blood pressur e is 142/88 mm Hg. Physical examination shows left - sided hemiparesis. The tongue deviates to the right when protruded. Sensation to pinprick and temperature is normal, and proprioception and sensation to light touch are absent over the left upper and lower extremities. Which of the following labeled sites in the photograph of a cross section of a normal brain stem is most likely damaged in this patient? 90. A 4 - year - old boy is brought to the physician because of slow growth during the past year. He has ha d recurrent urinary tract infections since the age of 1 year. He is at the 10th percentile for height and 25th percentile for weight. Physical examinat ion shows pallor. Laboratory studies show a normochromic, normocytic anemia and increased serum concentra tions of urea nitrogen and creatinine. Urinalysis shows a low specific gravity. Which of the following sets of additional serum findings is most likely in this patient? - Dihydroxycholecalciferol Calcium Inorganic Phosphorus 1,25 Erythropoietin (A) ↑ ↑ ↑ ↓ (B) ↑ ↑ ↓ ↓ ↓ (C) ↑ ↑ ↓ (D) ↓ ↑ ↑ ↓ ↓ ↑ ↓ ↓ (E) ↑ (F) ↓ ↓ ↑ 34

36 minutes after she fell A 42 year - old woman is brought to the emergency department because of double vision that began 20 - 91. Examination of the face shows ecchymoses over the left zygomatic from her horse and landed on the left side of her face. arch. A CT scan of the head is shown. Which of the following arteries is at greatest risk for injury in this patient? Facial (A) Frontal (B) (C) Infraorbital (D) Lacrimal (E) Ophthalmic 92. A previously healthy 24 - year - old woman who is a college student comes to the office because of a 6 - month history of abdominal bloating, upper abdominal discomfort, and constipation. The symptoms are more severe when she is preparing for examinations but imp rove after bowel movements. She takes no medications. She does not smoke or use illicit drugs. She 2 drinks alcoholic beverages occasionally. She is 160 cm (5 ft 3 in) tall and weighs 57 kg (125 lb); BMI is 22 kg/m . Her pulse Hg. Physical examination, including digital rectal examination, shows no other is 72/min, and blood pressure i s 100/72 mm abnormalities. A complete blood count and serum electrolyte concentrations are within the reference ranges. A urease breath test result is negative. Upper and lower endoscopies show no abnormalities. Which of the following is the most appropriate pharmacotherapy for this patient? Azathioprine (A) (B) Infliximab (C) Lubiprostone (D) Mesalamine (E) Sulfasalazine A 32 93. - year - old man is brought to the emergency departmen t 30 minutes after being struck by a car while driving his motorcycle. He reports severe pelvic pain. On examination, there is bruising of the perineum and pain is elicited with motion penile trauma. A plain x - of his pelvis. Blood is noted at the urethral meatus. There is no other ray shows a fracture of the superior pubic ramus and retrograde urethrography is done to evaluate for a urethral disruption. Which of the following portions of the urethra would be at greatest risk for injury in this patient? (A) Intramural (pre - prostatic) (B) Membranous (C) Prostatic Spongy (D) 35

37 day history of severe pain, swelling, and redness of his A 2 year - old boy is brought to the office by his mother because of a 1 - 94. - area. She says he has been eating poorly during this period, but left thumb. The mother does not recall any trauma to the otherwise he has been behaving normally. He has no history of major medical illness and receives no medications. He le for weight. His temperature is 37.7°C (99.8°F), appears tearful. He is at the 90th percentile for length and 80th percenti pulse is 100/min, respirations are 20/min, and blood pressure is 100/50 mm Hg. Physical examination shows an oral vesicle, cervical lymphadenopathy, and the findings in the photograph. Which of the followi ng types of infectious agents is the most likely cause of the findings in this patient’s finger? DNA virus (A) negative bacterium Gram - (B) (C) - positive bacterium Gram (D) RNA virus (E) Yeast old woman with active ankylosing spondylitis comes A 46 - year - 95. to the office for a follow - up examination. The use of various conventional nonsteroidal anti - inflammatory drugs has been ineffective. Sulfasalazine treatment also has not resulted in improvement. The most appropriate next step in treatment is administratio n of a drug that inhibits which of the following? (A) CD20 (B) - 2 Cyclooxygenase (C) Cytotoxic T - lymphocyte antigen 4 (D) Epidermal growth factor (E) Interleukin - 1 (IL - 1) (F) Tumor necrosis factor α 96. During a study of renal glomeruli, a healthy animal kidney is kept in a vascular bath preparation at a constant afferent arterial pressure of 100 mm Hg. If the efferent arteriole is constricted with a vascular clamp, which of the following Starling forces is most likely to change in the glomeruli? (A) Decr eased filtration coefficient (K ) f Decreased hydrostatic pressure (B) (C) Decreased oncotic pressure (D) Increased hydrostatic pressure Increased oncotic pressure (E) 36

38 A 67 97. year - old woman is brought to the emergency department 30 minutes after she had a generalized tonic - clonic seizure. - Her family says that she seemed mildly confused before her eyes rolled backward and she had the onset of uncontrollable and bit her tongue. jerking movements of her arms and legs and loss of consciousness. During the seizure, she passed urine - - lb) weight loss despite no At the scene, her vital signs were within normal limits. She has a 6 kg (15 - month history of a 7 changes in appetite. She received the diagnosis of small cell carcinoma of the lung last week and has not begun treatment. She has hypertension well controlled with lisinopril. On arrival, she is awake but does not respond to verbal stimuli. She is mm Hg while supine. not in distress. Her temperature is 37°C (98.6°F), pulse is 70/min, and blood pressure is 130/88 xamination shows no abnormalities. Laboratory studies show: E Serum + Na 115 mEq/L + 4 mEq/L K − Cl 81 mEq/L − HCO 25 mEq/L 3 9 mg/dL Urea nitrogen Glucose 102 mg/dL Creatinine 0.6 mg/dL Urine 60 mEq/L Sodium Potassium 20 mEq/L Osmolality 900 mOsmol/kg H O 2 Which of the following is the most likely diagnosis? (A) Adrenal insufficiency Diuretic abuse (B) (C) Heart failure (D) Syndrome of inappropriate secretion of ADH (vasopressin) (E) Water intoxication A 23 - year - old woman comes to the physician for genetic counseling prior to conception. Her brother and maternal uncle had 98. Duchenne muscular dystrophy (DMD) and died at the ages of 28 and 17 years, respectively. Genetic analysis was not performed on either relative prior to death. Serum s U/L (N=22 – tudies show a muscle creatine kinase concentration of 120 198). The patient's 50 - year - old mother has a serum muscle creatine kinase concentration of 300 U/L. Which of the following is the most appropriate assessment of this patient's carrier stat us for this disease? (A) The patient has a 50% risk for developing DMD (B) The patient has a 50% risk of having a child with DMD (C) The patient is a carrier of the disease based on her family history of DMD ed on her normal creatine kinase concentration (D) The patient is not a carrier of the DMD bas The patient's DMD carrier status is uncertain because of random X inactivation (E) 99. A randomized controlled trial is conducted to assess the risk for development of gastrointestinal adverse effects using azithromycin compared with erythromycin in the treatment of pertussis in children. Of the 100 children with pertussis enrolled, 50 receive azithromycin, and 50 receive erythromycin. Results show vomiting among 5 patients in the azithromycin group, compared patients in the erythromycin group. Which of the following best represents the absolute risk with 15 reduction for vomiting among patients in the azithromycin group? (A) 0.1 (B) 0.2 (C) 0.33 (D) 0.67 0.8 (E) 37

39 100. year - old woman comes to the office because of a 3 - day history of severe right back pain. She has not had any fever, - A 35 chills, or weight loss. She has no history of major medical illness. Musculoskeletal and neurologic examinations show no l, the patient becomes tearful and demands an MRI of her back abnormalities. When told that her examination is norma because her mother just died from breast cancer metastatic to bone and she fears that she may also have cancer. The patient already contacted her insurance company, who told her that if she has neurologic abnormalities an MRI may be covered by her plan. The patient asks the physician to order the MRI indicating that she has neurologic findings. Which of the following is the most appropriate initial action by the physician? (A) Advise the patient to change insurance companies as soon as she is able so that she can receive more comprehensive medical care Explain that the patient does not need the MRI and that it is not appropriate to misrepresent her examination findings (B) Immediately inform the patient's insurance company about what the patient has asked the physician to do (C) (D) Order the MRI as the patient requests (E) Recommend that the patient pay for the MRI out - of - pocket in order to ease her worry 101. A 6 - day - old breast - fed boy is brought t o the emergency department by his mother because of poor weight gain and irritability since delivery, and a 2 hour history of vomiting. Physical examination shows jaundice and hepatomegaly. A reducing - substance test result of the urine is positive, and a g lucose oxidase test result is negative. The concentration of which of the following metabolites in liver is most likely increased in this patient? (A) Fructose 1,6 - bisphosphate (B) Galactose 1 - phosphate Glucose 1 - (C) phosphate (D) - phosphate Glucose 6 A 14 - 102. - old boy is brought to the physician because of a 2 - day history of a sore throat and fever that peaks in the late year afternoon. He also has a 1 - week history of progressive fatigue. He recently began having unprotected sexual intercourse with one partne r. He appears ill. His temperature is 39°C (102.2°F). Physical examination shows cervical lymphadenopathy and pharyngeal erythema with a creamy exudate. Which of the following is the most likely diagnosis? (A) Candidiasis (B) Herpangina (C) Infectious mononucleosis (D) Mumps (E) Syphilis 103. In a cohort study of elderly women, the relative risk ratio for hip fractures among those who exercise regularly is 1.2 (95% confidence interval of 1.1 to 1.8). Which of the following is the most appropriate conclusio n about the effect of regular exercise on the risk for hip fracture? (A) Statistically nonsignificant increase in risk (B) Statistically nonsignificant overall decrease in risk (C) Statistically significant overall decrease in risk ficant overall increase in risk (D) Statistically signi 38

40 month history of pain below the left knee. His - year - old boy is brought to the physician by his mother because of a 1 - 104. A 12 es since this all began." mother says, "He can usually walk around, but he hasn't been able to play in any of his soccer gam Examination of the left knee shows warmth, swelling, and tenderness. An x - ray of the knee is shown. Which of the following structures is attached to the abnormal anterior tibial area? (A) Anterior cruciate ligament (B) Gastrocnem ius muscle (C) Patellar ligament (D) Popliteus muscle (E) Posterior cruciate ligament (F) Soleus muscle 105. week history of progressive - A 22 - year - old woman comes to the office because of a 3 - day history of cold symptoms and a 1 fatigue. Six weeks ago, she received a kidney transplant from a living, related donor. Immediately after the operation, she received monoclonal anti - CD3 therapy. Current medications are azathioprine, cyclosporine, and prednisone. Her temperature is 39°C (102.2°F). Physical examinatio n shows a well - healed surgical scar. Serum studies show that her urea nitrogen and creatinine concentrations have tripled. A diagnosis of allograft rejection is suspected. In addition, this patient's clinical presentation is best explained by an infection with which of the following agents? (A) Adenovirus (B) BK virus (C) Epstein - Barr virus (D) Herpes simplex virus - (E) Varicella zoster virus 39

41 106. patients with active untreat ed malaria A new test to detect the presence of malarial antibodies by ELISA is evaluated in 100 - borne parasites and in 100 patients with no history of infection. Results of testing are proven by demonstration of blood shown: Malaria Present Absent 75 5 80 Positive ELISA Test Results 25 95 120 Negative 100 100 200 Which of the following is the specificity of this test? (A) 65% 71% (B) 75% (C) (D) 94% (E) 95% 107. A 30 - year - old woman comes to the physician because of a 2 - day history of abdominal pain. She has a history of recurrent upper respiratory tract infections, sinusitis, and pancreatitis. She has thick nasal secretions. She says that her sweat is salty and crystallizes on her skin. Her vital signs are within normal limits. Physical examination shows epigastric tenderness. Genetic testing for the 36 most common m utations shows a detectable mutation (G551D) in one allele of the CFTR gene. Which of the following best explains this patient's clinical phenotype? Loss of heterozygosity of the CFTR gene has occurred in the pancreas (A) (B) ed in CFTR Only one G551D allele is need obligate carrier CFTR (C) The patient is a (D) The patient's CFTR mutation is unrelated to her clinical phenotype (E) The second CFTR mutation was not detected by the testing obtained 108. A 52 - year - old man is brought to the emergency department 30 minutes after he had an episode of chest pain radiating to his jaw while shoveling snow. His pulse is 80/min, and blood pressure is 130/70 mm Hg. The lungs are clear to auscultation. Cardiac examination shows an S . While undergoing an ECG, the patient sa ys that he feels the chest pain returning. The most 4 appropriate immediate treatment is a drug with which of the following mechanisms of action? (A) Increases cAMP concentration (B) Increases nitric oxide concentration Inhibits potassium flux (C) (D) Inhibits sodium flux 109. A technician wants to determine whether cytomegalovirus (CMV) DNA is present in the blood of a bone marrow transplant recipient. DNA purified from the leukocytes of the patient is reacted in a mixture containing oligonucleotides spec ific for CMV DNA, thermostable DNA polymerase, and nucleotides. Repetitive cycles of heating and cooling are performed, and the reaction product is detected by gel electrophoresis. The technician most likely used which of the following laboratory procedure s on this patient's blood? (A) Northern blotting (B) Polymerase chain reaction (C) Reverse transcription (D) Southern blotting (E) Western blotting 40

42 A 16 year - old boy comes to the physician because of a rash on his left inner thigh that first appeared - days after he returned 110. 2 from a hunting trip with friends in Minnesota. A photograph of the rash is shown. Without treatment, this patient is at increased risk for which of the following? Carditis (A) Glomerulonephritis (B) Hepatitis (C) Pancreatitis (D) (E) Thrombocytopenia 111. After being severely beaten and sustaining a gunshot wound to the abdomen, a 42 - year - old woman undergoes resection of a perforated small bowel. During the operation, plastic reconstruction of facial fractures, and open reduction an d internal fixation of the left femur are also done. Thirty six hours postoperatively, she is awake but not completely alert. She is - receiving intravenous morphine via a patient - controlled pump. She says that she needs the morphine to treat her pain, but s he is worried that she is becoming addicted. She has no history of substance use disorder. She drinks one to two glasses of wine weekly. Which of the following initial actions by the physician is most appropriate? (A) Reassure the patient that her chance of becoming addicted to narcotics is minuscule Maintain the morphine, but periodically administer intravenous naloxone (B) (C) Switch the patient to oral acetaminophen as soon as she can take medication orally (D) Switch the patient to intramuscular loraze pam (E) Switch the patient to intravenous phenobarbital 112. A 51 - year - old man comes to the office because of a 6 - month history of a lump on his tongue that is interfering with his riod. He has smoked 1 speech and eating; he also has had a 6.8 - kg (15 - lb) weight loss during this pe pack of cigarettes daily and has consumed six 12 - years. His vital signs are within normal oz bottles of beer on weekend nights during the past 30 - limits. Physical examination shows a 1.5 uation of the mass confirms cm mass on the apex of the tongue. Further eval squamous cell carcinoma. It is most appropriate to evaluate which of the following lymph nodes first for evidence of metastasis in this patient? (A) Inferior deep cervical (B) Parotid (C) Retropharyngeal (D) Submental Super (E) ior deep cervical 41

43 113. year - old woman comes to the physician because of a 2 - week history of malaise, nausea, vomiting, and decreased A 31 - cm (5 ft 5 in) tall and weig hs appetite. She is a known user of intravenous heroin. She appears chronically ill. She is 165 2 kg (103 lb); BMI is 17 kg/m . Her temperature is 36.7°C (98.1°F), pulse is 90/min, respirations are 18/min, and blood 47 mm Hg. Physical examination shows scleral icterus and a liver span of 16 cm. The spleen is not palpable. pressure is 114/68 udies show: Serum st Total bilirubin 3.2 mg/dL 774 U/L AST 820 U/L ALT negative HIV antibody Hepatitis B surface antigen negative Hepatitis B surface antibody positive - hepatitis B core antibody Anti positive Hepatitis B DNA negative Anti - hepatitis C virus positive Hepatitis C RNA positive Which of the following is the most likely outcome of this patient's infection? (A) Complete resolution of infection (B) Latent infection with intermittent viremia (C) Lifelong persistent infection Patient death fro (D) m acute infection - year - old man receives radiation therapy for a squamous cell carcinoma of the lung. Despite therapy, the tumor 114. A 57 progressively increases in size, and he dies 6 T P53 ), months later. His tumor cells contain a point mutation in the p53 gene ( leading to an inactive gene product. Based on this finding, the progressive tumor growth despite irradiation therapy is most likely to be related to a defect in cell cycle arrest in which of the following phases of the cell cycle? (A) G 0 G (B) 1 (C) G 2 (D) M (E) S 115. - year - old man comes to the physician for a routine physical examination. He is currently taking no medications. His A 55 Hg. Physical examination shows no other abnormalities. The presence of pulse is 80/min, and blood pressure is 165/95 mm which of the following mechanisms is most likely to increase this patient's blood pressure further? (A) Decreased cardiac output (B) Decreased pulse (C) Decreased stroke volume (D) Increased peripheral vascular resistance (E) Increased pulmonary artery pressure 42

44 116. - year - old man comes to the physician because of a 6 - month history of intermittent blood in his stool. He has had no pain A 53 - f the mass with defecation. Physical examination shows a 1 cm, visible anal mass located below the dentate line. A biopsy o is scheduled. If the mass if found to be malignant, it is most appropriate to evaluate which of the following lymph nodes for possible metastasis? Internal iliac (A) (B) Popliteal (C) Sacral Superficial inguinal (D) Superior rectal (E) 117. A 59 - year - old man is brought to the emergency department because of a 4 - day history of nausea, vomiting, and diarrhea. He also has been confused and agitated during this period. He has a history of mild hypertension. His current medication is a diuretic. His temperature is 37°C (98.6°F), pulse is 108/min, respirations are 26/min, and blood pressure is 70/47 mm Hg. Physical examination shows delayed capillary refill of the lips and nail beds and cool extremities. His oxyhemoglobin is 60% (N=70 – 75). These findings are most consistent with which of the following types of saturation in a central vein shock? (A) Cardiogenic (B) Distributive (C) Hypovolemic (D) Obstructive (E) Septic 43

45 USMLE STEP 1 SAMPLE TEST QUESTIONS ANSWER FORM FOR 40 – Block 1 (Questions 1 ) ___ 21. 1. ___ 31. 11. ___ ___ 32. ___ ___ 22. ___ 12. ___ 2. 3. ___ ___ 13. ___ 23. ___ 33. ___ 34. ___ 4. ___ 14. ___ 24. ___ ___ ___ 5. 15. ___ 25. 35. ___ ___ 26. 36. ___ 16. ___ 6. 7. 37. ___ ___ 17. ___ 27. ___ 28. ___ 38. ___ ___ 18. 8. ___ ___ ___ 39. ___ 9. ___ 19. 29. 30. 20. ___ ___ 10. ___ ___ 40. ) 80 – Block 2 (Questions 41 ___ 71. 51. ___ 41. 61. ___ ___ 62. ___ 42. ___ ___ 52. ___ 72. ___ ___ 73. ___ 43. ___ 53. 63. 64. ___ 74. ___ 54. ___ 44. ___ ___ 65. ___ 75. ___ 45. ___ 55. ___ 56. 76. ___ ___ 46. 66. ___ 67. 57. ___ ___ 47. ___ ___ 77. ___ ___ 68. 78. ___ 58. ___ 48. 49. 79. ___ ___ 59. ___ 69. ___ 70. ___ 50. ___ ___ 60. ___ 80. 117) Block 3 (Questions 81 – 101. 111. ___ 81. ___ ___ 91. ___ 82. ___ 112. ___ ___ 92. ___ 102. ___ 103. ___ 113. ___ 83. ___ 93. ___ 94. 114. ___ ___ 84. 104. ___ 105. 115. ___ ___ ___ 95. ___ 85. 86. ___ 116. ___ ___ 96. ___ 106. ___ 107. ___ 117. ___ 87. ___ 97. ___ 88. ___ 98. 108. ___ ___ ___ 99. ___ 89. 109. ___ 110. ___ 90. ___ 100. 44

46 ANSWER KEY FOR USMLE STEP 1 SAMPLE QUESTIONS TEST – ) 40 Block 1 (Questions 1 1. D 11. D 21. B 31. A 2. A 12. E 22. E 32. E 3. D 13. C 23. A 33. E 4. A 14. D 24. A 34. E 5. E 15. C 25. A 35. D 6. C 16. A 26. B 36. D 7. C 17. D 27. C 37. C 8. B 18. B 28. C 38. C 9. C 19. B 29. B 39. A 10. F 20. B 30. C 40. B Block 2 (Questions 41 – 80 ) 41. C 51. C 61. A 71. B 42. E 52. G 62. A 72. C 43. D 53. C 63. C 73. A 44. A 54. B 64. C 74. A 45. B 55. D 65. B 75. A 46. A 56. E 66. A 76. A 47. C 57. E 67. B 77. D 48. E 58. D 68. E 78. B 49. D 59. E 69. E 79. E 50. D 60. A 70. A 80. E – 81 Block 3 (Questions 117) 91. C 81. A 101. B 111. A 112. D 102. C 92. C 82. E 83. E 103. D 93. B 113. C 94. A 84. E 114. B 104. C 95. F 85. E 115. D 105. B 96. D 106. E 86. A 116. D 87. B 117. C 97. D 107. E 88. B 98. E 108. B 89. C 109. B 99. B 100. B 110. A 90. E 45

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