NBME Cheat Sheet 2026

The 30 highest-yield NBME facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. Secretin, released by duodenal S cells in response to acidic chyme, primarily acts to: → Stimulate pancreatic ductal bicarbonate secretion
2. A patient has no rise in venous lactate after forearm ischemic exercise test, but shows a normal ammonia rise. Which enzyme deficiency is most likely? → Myophosphorylase (McArdle disease)
3. A 40-year-old woman with systemic lupus erythematosus has a kidney biopsy showing 'wire loop' lesions. What is deposited in these capillary walls? → IgG and C3 immune complexes
4. A malnourished 45-year-old alcoholic presents with confusion, ophthalmoplegia, and ataxia. What is the most urgent intervention? → IV thiamine before glucose
5. A new drug reduces the absolute risk of myocardial infarction from 4% to 2% over 5 years. The number needed to treat (NNT) is: → 50
6. Which organism is responsible for gas gangrene and produces an alpha toxin (lecithinase) that destroys cell membranes by cleaving phospholipids? → Clostridium perfringens
7. Neuronal loss in the caudate nucleus with expanded CAG trinucleotide repeat inheritance causes which disorder? → Huntington's disease
8. The white pulp of the spleen is organized around central arterioles and is primarily composed of which cell type? → T and B lymphocytes
9. A patient with familial hypercholesterolemia has markedly elevated LDL. The primary defect impairs which cellular process? → Receptor-mediated endocytosis of LDL particles
10. A 2-year-old ingests unknown pills from a grandmother's purse and develops bradycardia, miosis, excessive salivation, and bronchospasm. Most likely substance? → Organophosphate compound
11. Pseudostratified ciliated columnar epithelium with goblet cells is the hallmark lining of which anatomical region? → Trachea and primary bronchi
12. During the cross-bridge cycle, what event directly produces the power stroke in skeletal muscle? → Release of ADP and inorganic phosphate from myosin after actin binding
13. A newborn is found to have a patent ductus arteriosus. Which auscultatory finding is most characteristic? → Continuous machine-like murmur at the left infraclavicular area
14. A medical student channels her anxiety about the upcoming board exam into long hours of productive studying. This defense mechanism is best described as: → Sublimation
15. Prednisone is prescribed for an acute asthma exacerbation. Which mechanism is responsible for its anti-inflammatory effect? → Binds glucocorticoid receptor → inhibits NF-κB → decreases cytokine transcription
16. The specificity of a diagnostic test is BEST defined as: → True negatives / (True negatives + False positives)
17. During embryonic development, failure of the pleuroperitoneal membrane to close results in which congenital defect? → Congenital diaphragmatic hernia
18. During embryogenesis, failure of neural crest cell migration to the foregut leads to which condition? → Hirschsprung disease
19. Which of the following is an example of PRIMARY active transport? → Na+/K+-ATPase
20. Which feature distinguishes cardiac muscle from both skeletal and smooth muscle on light microscopy? → Intercalated discs
21. Translation initiation in eukaryotes begins when the ribosome scans the 5' mRNA cap to find the start codon. Which amino acid is encoded by AUG in eukaryotes? → Methionine
22. During synaptic transmission at the neuromuscular junction, which event directly triggers vesicle fusion and acetylcholine release? → Calcium influx through voltage-gated P/Q-type channels
23. Which opioid analgesic is most appropriate for a patient with severe renal impairment requiring chronic pain management? → Fentanyl
24. Pain and temperature from the body ascend to the thalamus via which pathway, and where do they first synapse after entering the spinal cord? → Lateral spinothalamic tract; dorsal horn (Rexed laminae I and V)
25. Which glycolytic intermediate directly donates phosphate to ADP to produce ATP via substrate-level phosphorylation? → Phosphoenolpyruvate
26. Carnitine is required for transport of long-chain fatty acids across which membrane? → Inner mitochondrial membrane
27. Huntington disease is caused by which type of mutation in the HTT gene? → Trinucleotide (CAG) repeat expansion
28. A child is brought to the ER after ingesting penicillin tablets. Allergic reaction to penicillin is most commonly mediated by which mechanism? → Type I (IgE-mediated) hypersensitivity
29. Which enzyme catalyzes the rate-limiting step of the pentose phosphate pathway and is important for NADPH production in red blood cells? → Glucose-6-phosphate dehydrogenase
30. A 2-year-old presents with an abdominal mass crossing the midline, hypertension, raccoon eyes, and an elevated urine catecholamine level. Most likely diagnosis? → Neuroblastoma