NBME CBSE (USMLE Step 1) Simplified Test Bank Latest Exam 2026/2027| A Comprehensive Review of 931 Practice Questions and Multichoice Answers with Detailed Rationales| Already Graded A+

NBME CBSE (USMLE Step 1) Simplified Test Bank Latest Exam 2026/2027| A Comprehensive Review of 931 Practice Questions and Multichoice Answers with Detailed Rationales| Already Graded A+ ________________________________________ Table of Contents Section 1: Cardiovascular System (Questions 1-120) 1.1 Cardiac Physiology & Anatomy 1.2 ischemic heart disease 1.3 Heart Failure & Cardiomyopathies 1.4 Valvular Heart Disease 1.5 Arrhythmias & Conduction Disorders 1.6 vascular disease & Hypertension Section 2: Pulmonary System (Questions 121-190) 2.1 Respiratory Physiology 2.2 Obstructive Lung Disease 2.3 Restrictive Lung Disease 2.4 Infectious Lung Disease 2.5 Lung Cancer Section 3: Gastrointestinal System (Questions 191-280) 3.1 Upper GI Disorders 3.2 Lower GI Disorders 3.3 Hepatic Disorders 3.4 Pancreatic & Biliary Disorders 3.5 Malabsorption Section 4: Renal & Urinary System (Questions 281-360) 4.1 Renal Physiology 4.2 Glomerular Disease 4.3 Tubulointerstitial Disease 4.4 Acute Kidney Injury 4.5 Chronic Kidney Disease 4.6 Electrolyte Disorders Section 5: Endocrine System (Questions 361-430) 5.1 Thyroid Disorders 5.2 Adrenal Disorders 5.3 Pituitary Disorders 5.4 Diabetes Mellitus 5.5 Calcium & Bone Metabolism Section 6: Reproductive System (Questions 431-500) 6.1 Male Reproductive 6.2 Female Reproductive 6.3 Pregnancy & Obstetrics 6.4 Gynecologic Oncology Section 7: Hematology (Questions 501-590) 7.1 Anemias 7.2 Leukemias & Lymphomas 7.3 Coagulation Disorders 7.4 Transfusion Medicine Section 8: Neurology (Questions 591-680) 8.1 Neuroanatomy 8.2 Stroke & Vascular Disorders 8.3 Demyelinating Diseases 8.4 Movement Disorders 8.5 Neuromuscular Disorders 8.6 Seizures & Epilepsy Section 9: Psychiatry (Questions 681-750) 9.1 Mood Disorders 9.2 Anxiety Disorders 9.3 Psychotic Disorders 9.4 Personality Disorders 9.5 Substance Use Disorders Section 10: Immunology & Infectious Disease (Questions 751-850) 10.1 Innate & Adaptive Immunity 10.2 Immunodeficiencies 10.3 Autoimmune Diseases 10.4 Bacterial Infections 10.5 Viral Infections 10.6 Parasitic Infections Section 11: Musculoskeletal & Dermatology (Questions 851-940) 11.1 Bone Disorders 11.2 Joint Disorders 11.3 Muscle Disorders 11.4 Skin Conditions Section 12: Biostatistics & Epidemiology (Questions 941-1000) 12.1 Study Design 12.2 Measures of Disease Frequency 12.3 Diagnostic Test Characteristics 12.4 Bias & Error Section 13: Pharmacology (Questions ) 13.1 Pharmacokinetics 13.2 Cardiovascular Drugs 13.3 Antimicrobial Agents 13.4 CNS Drugs Section 14: Embryology & Developmental Milestones (Questions ) 14.1 Embryologic Development 14.2 Congenital Anomalies 14.3 Developmental Milestones ________________________________________ SECTION 1: CARDIOVASCULAR SYSTEM Question 1 A 65-year-old man with hypertension presents with sudden onset of severe tearing chest pain radiating to his back. Blood pressure is 180/95 mmHg in the right arm and 140/80 mmHg in the left arm. Which of the following is the most likely diagnosis? A) Acute myocardial infarction B) Pulmonary embolism C) Aortic dissection D) Pericarditis Answer: C) Aortic dissection Rationale: The classic presentation of aortic dissection is sudden, severe "tearing" chest pain that radiates to the back. Unequal blood pressures between arms (due to involvement of subclavian arteries) and hypertension are key features. Acute MI presents with crushing substernal pain without radiation to back and no BP differential. Pulmonary embolism presents with acute dyspnea, chest pain, and hypoxia. Pericarditis presents with sharp, pleuritic pain that improves when leaning forward. ________________________________________ Question 2 A 70-year-old man is brought to the emergency department with crushing substernal chest pain that began 2 hours ago. ECG shows ST elevation in leads V1-V4. Which of the following would be the most appropriate immediate management? A) Sublingual nitroglycerin B) Aspirin and thrombolytics C) IV heparin and warfarin D) Percutaneous coronary intervention (PCI) Answer: D) Percutaneous coronary intervention (PCI) Rationale: ST elevation in V1-V4 indicates an anterior wall ST-elevation myocardial infarction (STEMI). PCI is the preferred reperfusion strategy if available within 90-120 minutes of arrival. Aspirin should be given immediately but thrombolytics are used if PCI is not available. Nitroglycerin is used for symptom relief but is not definitive. Heparin and warfarin are used for anticoagulation but do not reopen occluded arteries. The gold standard for STEMI is urgent reperfusion via PCI. ________________________________________ Question 3 A 55-year-old woman with a history of hypertension presents with progressive dyspnea on exertion, orthopnea, and paroxysmal nocturnal dyspnea. Physical examination reveals an S3 gallop and crackles in the lung bases. Which of the following best explains the pathophysiology of her symptoms? A) Decreased cardiac output leading to renal sodium retention B) Increased left ventricular end-diastolic pressure leading to pulmonary congestion C) Right ventricular hypertrophy D) Decreased systemic vascular resistance Answer: B) Increased left ventricular end-diastolic pressure leading to pulmonary congestion Rationale: Left-sided heart failure leads to increased left ventricular end-diastolic pressure, which is transmitted backward to the left atrium, pulmonary veins, and pulmonary capillaries, causing pulmonary congestion. This manifests as dyspnea, orthopnea, paroxysmal nocturnal dyspnea, and crackles on auscultation. An S3 gallop indicates a dilated, failing ventricle. Option A describes the renin-angiotensin-aldosterone system activation but is not the primary cause of pulmonary symptoms. Right ventricular hypertrophy would be seen in right-sided failure. Decreased SVR is not characteristic of heart failure. ________________________________________ Question 4 A 72-year-old man with a history of coronary artery disease is in the ICU with acute decompensated heart failure. Which of the following laboratory findings would most support the diagnosis of heart failure? A) Elevated troponin I B) Elevated B-type natriuretic peptide (BNP) C) Elevated creatine kinase-MB D) Elevated C-reactive protein Answer: B) Elevated B-type natriuretic peptide (BNP) Rationale: BNP is a hormone secreted by cardiac ventricles in response to increased wall tension and volume overload. BNP levels are elevated in heart failure and correlate with the severity of the disease. Troponin I and CK-MB are markers of myocardial injury, not specific to heart failure. CRP is a marker of inflammation and is not specific to heart failure. ________________________________________ Question 5 An 80-year-old woman presents with syncope, chest pain, and dyspnea on exertion. Cardiac auscultation reveals a harsh, crescendo-decrescendo systolic murmur best heard at the right upper sternal border that radiates to the carotids. Which of the following is the most likely diagnosis? A) Aortic stenosis B) Mitral regurgitation C) Tricuspid stenosis D) Pulmonic stenosis Answer: A) Aortic stenosis Rationale: The classic triad of aortic stenosis is syncope, angina (chest pain), and dyspnea (SAD). The murmur is a harsh, crescendo-decrescendo systolic ejection murmur best heard at the right upper sternal border (aortic area) with radiation to the carotids. Mitral regurgitation produces a holosystolic murmur at the apex radiating to the axilla. Tricuspid stenosis produces a diastolic murmur at the left lower sternal border. Pulmonic stenosis produces a systolic murmur at the left upper sternal border.