Which nerve is the largest in the body and runs from the spine to the foot?

• A. Sciatic nerve
• B. Sternum
• C. Scoliosis
• D. Scaphoid bone

Answer: (A)

The key idea is identifying the largest nerve and tracing its course from the spine to the foot. The sciatic nerve is the largest nerve in the body by diameter and is among the longest. It forms from nerve roots in the lower spine (L4 through S3) and exits the pelvis through the greater sciatic foramen, typically below the piriformis muscle, then runs down the back of the thigh. It supplies most of the posterior thigh muscles and, as it travels, divides near the knee into the tibial and common fibular (peroneal) nerves, which continue down to the foot. That long path from the spine to the foot is what makes it the largest nerve. The other options aren’t nerves: the sternum is a chest bone, scoliosis is a spinal curvature, and the scaphoid is a wrist bone.