Pelvic diaphragm
- Levator ani
- Largest and most important muscle of pelvic floor
- Arises posterior aspect of body of pubic bone, fascia of side wall of pelvis (covering obturator internus) and spine of ischium
- Coccygeus
- Superifical muscles of anterior and posterior perineum
Anterior (Urogenital perineum)
- Line joining ischial tuberosities passes just in front of anus
- Attached to sides of triangle is tough fascial sheet - perineal membrane (pierced by urethra), deep to membrane is external uretheric sphincter
- Enclosing deep aspect of external sphincter is second fascial sheath
- Superficial to perineal membrane is superficial perineal pouch, contains:
- Bulbospongiosus (covers corpus spongiosum surrounding urethra)
- Ischiocavernosus (on each side) arising from ischial ramus and covering corpus cavernosum
- Superficial transverse perineal muscle - runs transversely from perineal body to ischial ramus (of no functional importance)
Posterior (anal) perineum
- Triangle lying between ischial tuberosities and the coccyx
- Contents:
- Anus
- Superficial sphincters
- Levator ani
- Ishiorectal fossa (lined with lobulated fat); communicate with each other behind the anus - infection on one side readily passess to other