The pudendal nerve leaves the pelvic cavity through the greater sciatic foramen and then immediately enters the perineum inferiorly to the pelvic floor by passing around the ischial spine and through the lesser sciatic foramen (Fig. 5.15). The ischial spine can be palpated transvaginally in women and is the landmark that can be used for administering a pudendal nerve block.
Parasympathetic innervation from spinal cord levels S2 to S4 controls erection