The University of Maryland Medical Center, Drugs.com and Nucleus Medical Media websites all have diagrams of sciatica. The diagrams on these pages illustrate the sciatic nerve and how the brain interprets the pain signals it sends.
Sciatica is a symptom of various conditions and refers to pain, numbness, weakness or tingling in the leg, notes the University of Maryland Medical Center. Injury to the sciatic nerve, which starts in the lower spine and runs down each leg, causes this condition. Potential sources of injury include a slipped disk, spinal stenosis, piriformis syndrome, pelvic injury or tumors. Most people with this condition experience pain on one side of the body, and the amount and affected areas of pain vary by individual. This site's diagram illustrates the sciatic nerve as it runs down a leg and how the radiating pain travels downward.
The diagram on Drugs.com illustrates the various causes of sciatica, as well. It shows sciatica on one side of the body and how different causes irritate the sciatic nerve. The image on Nucleus Medical Media shows sciatica on the opposite leg and also illustrates the male pelvis, lower extremities, bones of the lower spine and legs, major nerves, the sciatic nerve, and nerves to the lower extremities.