PELVIS

• lumbosacral plexus
  • dorsal division
    • Superior gluteal nerve: IA, LS, S1
    • 2 Inferior gluteal nerve: LS, SI, S2
    • 3 erve to piriformis: Sl, S2.
    • 4 Perforating cutaneous nerve: S2, S3.
  • ventral division
    • Nerve to quadratus femoris: L4, LS , Sl.
    • nerve to obturator internus: LS, Sl, S2.
    • Pudendal nerve: S2, S3, S4: Supplies
      • and the sphincter ani extemus,
      • all muscles in urogenital triangles.
    • Muscular branches
      • including perineal branch of nerve S4.
      • to the levator ani, the coccygeus
    • 5 Pelvic splanchnic nerves: S2, S3 , S4.
  • both dorsal and ventral division
    • sciatic nerve
      • common peroneal nerve
      • tibial nerve
    • posterior cutaneous nerve of thigh
  • pelvic floor
    • pelvic diaphragm
  • pelvis is divided by the plane of pelvic inlet or superior aperture of pelvis in to 2 parts
    • lesser pelvis or true pelvis
      • bony walls
        • anteriorly pubic symphysis and body of pubic bones
        • posteriorly by sacrum and coccyx
      • ligaments
        • obturator membrane
        • sacrotuberous and sacrospinous ligament
      • muscles
        • obturator internus
        • piriformis
    • greater pelvis or false pelvis
  • internal iliac artery
  • Branches
    • Medial
      • Peritoneum and to a few tributaries of the
      • internal iliac vein.
    • Lateral
      • External iliac vessels and obturator nerve
    • Posterior
      • Internal iliac vein, lumbosacral trunk and
        • the sacroiliac joint (see Figs 24.27 and 34.7)
    • Anterior
      • In female, it is related to the ovary and
        • lateral end of the uterine tube (see Fig. 31.1)
          • and ureter
  • supplies
    • pelvic organ
    • Perineum.
    • Greater part of the gluteal region.
    • Iliac fossa.
  • course
    • the internal iliac artery begins in front of the sacroiliac joint, at the level of the intervertebral disc between the fifth lwnbar vertebra and the sacrum
    • lies medial to the psoas major muscle.
    • The arltery runs downwards and backwards, and ends near thee upper margin of the greater scia tic notch, by dividing into anterior and posterior divisions or trunks
  • branches
    • anterior division
      • 1 Superior vesical
        • proximal 2..5 cm is persistent umbilical artery
      • 2 Obturator
        • medially crossed by ductus deferens and ureter
      • 3 Middle rectal
      • 4 Inferior vesical
        • in female replaced by vaginal artery
          • vagina , bulb of vestibule
          • base of urinary bladder
        • trigone of bladder , prostrate,seminal vesicles
      • 5 Inferior gluteal
        • largest branch
        • axial branch of lower limb
        • supplies buttock and back of thigh
        • enters the gluteal region through lower part of greater sciatic foramen
      • 6 Internal pudendal. The last t:wo are the terminal
        • in females it if 7th branch uterine artery
          • supplies vagina , cervix, fallopian tube
    • posterior division
      • 1 Iliolumbar.
      • 2 Two lateral sacral.
      • 3 Superior gluteal arteries
• Structures crossing pelvic inlet or brim
  • Median sacral vessels
  • 2 Sympathetic trunk.
  • 3 Lumbosacral trunk
  • 4 Iliolumbar artery.
  • 5 Obturator nerve.
  • 6 Internal iliac vessels
  • 7 Medial limb of sigmoid mesocolon with superior
    • rectal vessels-left side only
  • 8 Ureter
  • 9 Sigmoid colon- on left side only.
  • 10 Ovarian vessels in female
  • 11 Ductus deferens in male/ round ligament of uterus
    • in female
  • 12 Lateral umbilical ligament
  • 13 Median umbilical ligamen t or urachus
  • 14 Autonomic nerve plexuses.
  • 15 Coils of intestine and pregnant uterus.
  • 16 Full urinary bladder.