Intervertebral Foramina The sciatic nerve starts as a collection of nerve fibers, or roots, in the lower spine. These fibers exit the spinal canal through foramina (plural of foramen), small openings between each pair of vertebrae. Further Reading: Sciatic Nerve Anatomy Related Articles Sciatic Nerve and SciaticaTypes of Sciatic Nerve PainAnatomy Of Nerve Pain Related Videos Sciatic Nerve Anatomy VideoWatch an animated video detailing the anatomy of the sciatic nerve. Sciatica Animated VideoSciatica is leg pain caused by a problem in the low back. Watch an animated video that details the causes and symptoms of sciatica. Sciatica Causes and Treatments VideoLearn about the possible causes of sciatica and the various treatment options such as medications, exercise, surgery, and steroid injections.