What are the main ligaments in the gluteal region and what do they do?

The two main ligaments are the sacrotuberous ligament (from lateral sacrum/coccyx to ischial tuberosity) and sacrospinous ligament (from ischial spine to sacrum/coccyx). Their key function is to convert the sciatic notches into the greater and lesser sciatic foramina, creating gateways for structures between the pelvis, gluteal region, and perineum.

What structures pass through the greater sciatic foramen?

The greater sciatic foramen is a major passageway for neurovascular structures entering the gluteal region from the pelvis. It is divided by the piriformis muscle: above it pass the superior gluteal nerve and vessels; below it pass the inferior gluteal nerve and vessels, sciatic nerve, posterior cutaneous nerve of thigh, nerve to quadratus femoris, pudendal nerve, internal pudendal vessels, and nerve to obturator internus.

How do the pudendal nerve and internal pudendal artery travel through the sciatic foramina?

The pudendal nerve and internal pudendal artery exit the pelvis through the greater sciatic foramen (below piriformis). They then loop over the sacrospinous ligament and ischial spine to enter the perineum via the lesser sciatic foramen, where they travel in the pudendal canal.

What is the role of the piriformis muscle in the greater sciatic foramen?

The piriformis muscle is a key landmark that fills the greater sciatic foramen, dividing it into superior and inferior compartments. This division helps organize the passage of structures: nerves and vessels pass either above or below the piriformis to reach the gluteal region.

What structures pass through the lesser sciatic foramen?

The lesser sciatic foramen serves as a passage for structures entering the perineum from the gluteal region. Key structures include the tendon of obturator internus, nerve to obturator internus, internal pudendal vessels, and pudendal nerve.

Why are the sciatic foramina important in anatomy?

The sciatic foramina are crucial gateways that allow neurovascular and muscular structures to transition between the pelvis, gluteal region, and perineum. They facilitate the passage of major nerves (like the sciatic and pudendal nerves) and blood vessels, enabling function and sensation in the lower limb and perineal areas.

Gluteal Ligaments & Sciatic Foramina – Anatomy