- Ischiorectal fossa (ischioanal fossa): wedge-shaped, fat-filled space on each side of the anal canal, below the pelvic diaphragm.
surface view of the ischiorectal fossa and perineal membrane Surface view of the ischiorectal fossa and perineal membrane.
Extent, Dimensions and Communication
- Base lies on the skin over the anal region of the perineum; apex is directed upwards and laterally.
- Each fossa measures about 5 cm in length, width and depth; depth may be slightly more.
- The two fossae communicate with each other behind the anal canal.