Anatomical variants Practice Questions
20 free Anatomical variants practice questions for the USMLE Step 1, each with the correct answer and a detailed explanation. Open any question below, or take the full set as an interactive quiz.
Questions
20 questions
All Anatomical variants questions
- Q1. During a laparoscopic cholecystectomy, a surgeon identifies an accessory bile duct draining directly into the gallbladder. This is most consistent with which a…
- Q2. A CT scan reveals a right-sided aortic arch in an asymptomatic adult. This variant most commonly results from persistence of which embryologic structure?
- Q3. An MRI shows a duplicated inferior vena cava (IVC). This finding results from persistence of which structure?
- Q4. A patient is found to have an arcuate uterus during evaluation for infertility. This variant is due to incomplete resorption of which embryologic structure?
- Q5. A surgeon notes that the right renal artery passes anterior to the IVC instead of posterior. This represents which vascular variant?
- Q6. Ultrasound reveals a retroesophageal right subclavian artery (arteria lusoria). Patients with this variant may present with which symptom?
- Q7. A patient undergoing MRI is found to have a horseshoe kidney. This occurs due to fusion of the kidneys at which location?
- Q8. A neonate has a persistent median artery supplying the forearm. This artery is a remnant of which developmental vessel?
- Q9. A surgeon encounters an accessory spleen during a splenectomy. Where is the most common location for this structure?
- Q10. An abdominal CT reveals a retroaortic left renal vein. This variant predisposes to which condition?
- Q11. A patient has a tracheal bronchus arising directly from the trachea. This variant is most likely to affect which lung region?
- Q12. A patient has absence of the palmaris longus tendon bilaterally. This variant most commonly affects which action?
- Q13. During pelvic surgery, the surgeon notes an obturator artery arising from the inferior epigastric artery. This is referred to as which variant?
- Q14. Imaging reveals a duplicated ureter on the right side. This is due to duplication of which embryologic structure?
- Q15. A patient is diagnosed with pectus excavatum. This chest wall variant involves abnormal development of which structure?
- Q16. During carotid surgery, the surgeon encounters a high carotid bifurcation at the level of the hyoid bone. This variation affects which anatomical landmark?
- Q17. A CT scan identifies a persistent left superior vena cava (PLSVC). This venous variant most commonly drains into which structure?
- Q18. A patient has a cervical rib arising from C7. This variant increases risk for which condition?
- Q19. Imaging reveals a Meckel diverticulum. This anomaly results from incomplete obliteration of which structure?
- Q20. A patient is found to have a bifid (split) median nerve at the wrist. This variant is most clinically associated with which condition?