The greater and lesser sciatic foramina are two openings in the posterior aspect of the pelvis. The greater sciatic foramen is larger and is separated from the lesser sciatic foramen by the sacrospinous ligament. In this article, we shall look at the anatomy of the greater sciatic foramen and lesser sciatic foramen – their borders and contents. Pro Feature - 3D Model You've Discovered a Pro Feature Access our 3D Model Library Explore, cut, dissect, annotate and manipulate our 3D models to visualise anatomy in a dynamic, interactive way. Learn More Greater Sciatic Foramen The greater sciatic foramen provides a passageway for structures to pass from the pelvis into the gluteal region. Borders The greater sciatic foramen is bordered by: Superior – anterior sacroiliac ligament Posteromedial – sacrotuberous ligament Anterolateral – greater sciatic notch of the ilium Inferior – sacrospinous ligament and ischial spine By TeachMeSeries Ltd (2025) Fig 1The borders of the greater sciatic foramen. Contents The greater sciatic foramen is divided into two parts by the presence of the piriformis muscle – the suprapiriform and infrapiriform foramina. Suprapiriform foramen: Superior gluteal artery and vein Superior gluteal nerve Infrapiriform foramen: Sciatic nerve Pudendal nerve Inferior gluteal artery and vein Inferior gluteal nerve Posterior femoral cutaneous nerve Nerve to obturator internus Nerve to quadratus femoris By TeachMeSeries Ltd (2025) Fig 2The piriformis divides the greater sciatic foramen into two – the supra- and infrapiriform foramina. Pro Feature - Dissection Images The pudendal nerve leaves the pelvis through the lower part of the greater sciatic foramen. It then crosses the sacrospinous ligament, and then re-enters the pelvis through the lesser sciatic foramen. The pudendal nerve leaves the pelvis through the lower part of the greater sciatic foramen. It then crosses the sacrospinous ligament, and then re-enters the pelvis through the lesser sciatic foramen. You've Discovered a Pro Feature Access our Dissection Image Library Enhance your understanding with high-resolution dissection images showcasing real-life anatomy. Learn More Lesser Sciatic Foramen The lesser sciatic foramen provides a communication between the perineum of the pelvis and the gluteal region. It lies inferiorly to the pelvic floor. Borders The lesser sciatic foramen is bordered by: Superior – sacrospinous ligament and ischial spine Anterior – ischial spine, lesser sciatic notch and ischial tuberosity Posterior – sacrotuberous ligament Contents The following structures pass through the lesser sciatic foramen: Internal pudendal artery and vein Pudendal nerve (note the pudendal nerve first leaves the pelvis via the greater sciatic foramen, and then re-enters via the lesser sciatic foramen) Obturator internus tendon Nerve to obturator internus By TeachMeSeries Ltd (2025) Fig 3The pudendal nerve first leaves the pelvis via the greater sciatic foramen, and then re-enters via the lesser sciatic foramen Do you think you’re ready? Take the quiz below Pro Feature - Quiz The Sciatic Foramina Question 1 of 3 Submitting... Skip Next Rate question: You scored 0% Skipped: 0/3 1800 More Questions Available Upgrade to TeachMeAnatomy Pro Challenge yourself with over 1800 multiple-choice questions to reinforce learning Learn More Print Article Rate This Article