Pudendal Nerve, Posterior View

Description

Emerging from the anterior rami of S2 to S4, the pudendal nerve is traced posteriorly as a stout trunk against the posterolateral pelvic wall, framed by the sacrum and the paired hip bones (ilium, ischium, and pubis). From this back view, its course can be followed as it passes inferior to the piriformis, exits the pelvis via the greater sciatic foramen, then hooks around the ischial spine and sacrospinous ligament to re-enter through the lesser sciatic foramen. Proximal relationships to the sciatic nerve and neighboring sacral plexus branches are apparent, with the pudendal trajectory turning anteroinferiorly toward the perineum. Bony landmarks read clearly. That bend at the ischial spine matters in practice because it is the classic compression and entrapment point in pudendal neuralgia, and it is also the landmark used for a transvaginal or transperineal pudendal nerve block (palpating the ischial spine and targeting the nerve near the sacrospinous ligament). A posterior depiction also reinforces the surgical geography of the greater and lesser sciatic foramina, where pelvic trauma, scarring, or iatrogenic sutures can affect the pudendal nerve while sparing or involving the adjacent sciatic nerve. Sensory loss of the posterior scrotum and penile skin, plus pain with sitting, fits this anatomy. Use this artwork for pelvic neuroanatomy teaching in gross anatomy and urogenital modules, and for illustrating chapters on chronic pelvic pain, perineal surgery, and regional anesthesia techniques. It also suits operative atlases discussing the ischial spine approach and the relationship of sacral plexus branches to the posterior pelvis. Anatomical accuracy verified by SciePro's Medical Advisory Board.