<prompt> Structure crossing dorsal surface of ischial spine are all exceptInternal pudendal vesselPudendal nerveObturator nerveNerve to obturator internus  <response>: Pudendal nerve, internal pudendal vessels, and nerve to obturator internus after leaving the pelvis through greater sciatic foramen, cross the dorsal aspect of the ischial spine and then re-enter the pelvis through the lesser sciatic foramen. 