Lecture Notes - Pelvic Neurovasculature

Vessels

• Common Iliacs
  • External Iliacs - vessel of lower limb
  • Internal Iliacs - pelvis, gluteals, medial thigh, perineum
• Internal Iliac - highly variable!!
  • posterior division - parietal branches only
    • iliolumbar
    • lateral sacral
    • superior gluteal
  • anterior division - parietal and visceral branches
    • inferior gluteal
    • obturator (30% aberrant)
    • internal pudendal (around sacrospinous ligament)
    • umbilical (1st branch off anterior division)
    • superior vesical (artery of the ductus deferens)
    • middle rectal
    • inferior vesical (prostatic branches)
    • uterine (relationship to ureter!!)
    • vaginal

Innervation

• Sacral Plexus
  • ventral primary rami of L4,5 (aka, lumbosacral trunk) and S1,2,3,4
  • relationship to piriformis muscle
• Autonomics
  • Inferior hypogastric plexus (sides of rectum) - continuation of preaortic plexus via hypogastric nerves
  • Sacral splanchnics - sympathetic fibers from sacral portion of sympathetic chain
  • Pelvic splanchnics - parasympathetic fibers from S2,3,4

Review Intro to Autonomics Module - this is the time to make it all come together!
Also, review the formation of the inferior hypogastric plexus (Pelvic Autonomics Module)

• where do sympathetics come from?
• where do parasympathetics come from?
• how are specific pelvic viscera innervated?

Pelvic Diaphragm/Floor

• Wall of Pelvic Cavity
  • Obturator Internus m.
    • Arcus Tendineus Levator Ani - attachment for portion of levator ani m.
  • Piriformis m. - exits pelvis via greater sciatic foramen, sacral plexus lays on piriformis
• Floor or Diaphragm
  • Above = pelvic cavity
  • Below = perineum
    • Coccygeus m. - on internal surface of sacrospinous ligament
    • Levator Ani m.
      • pubococcygeus
      • iliococcygeus
      • puborectalis
      • genital hiatus