Pelvic fascia

Parietal Pelvic Fascia

• On pelvic surface of Obturator Internus
• Strong membrane
• Fuses with the Periosteum at the upper margin of the Obturator Internus muscle
• Becomes thin below the Tendinous Arch where it covers Obturator Internus on the lateral wall of the Ischioanal Fossa
• Fascia on pelvic surface of Piriformis fuses with the periosteum at the medial margins of the Anterior Sacral Foramina
• Sacral Anterior Primary Rami emerges from these foramina thus lie behind the fascia
• Internal Iliac Vessels lie in front of the fascia over Piriformis
• Large Pre-sacral Lateral Sacral Veins lie initially behind this fascia as they emerge from the Anterior Sacral Foramina

Rectosacral Fascia

• A condensation of connective tissue from the front of the lower Sacrum

• Passes downwards and forwards to fuse with the Mesorectal Fascia 3-5cm proximal to the Anorectal Junction

• Large Pre-Sacral Lateral Sacral Veins lie behind this fascia on the front of the Sacrum

• Superior Fascia of the Pelvic Diaphragm

  • Fascia on the pelvic surface of Levator Ani and Coccygeus
  • Attached in front to the posterior surface of the Body of the Pubis and at the back to the Ischial Spine
  • In between attachments, it blends with the Obturator Fascia
  • Thickening of these two fused fasciae forms the Tendinous Arch of Origin of Levator Ani

• Inferior Fascia of the Pelvic Diaphragm

  • Thin fascia covering the undersurface of Levator Ani
  • On the sloping medial wall of the Ischioanal Fossa
  • Blends with the Obturator Fascia laterally
  • Blends with the fascia on the External Anal and Urethral Sphincters medially