Space
Perineum
The region between the pelvic diaphragm and the skin
High-yield
Pubic symphysis anterior, coccyx posterior, pubic arch and ischial tuberosities laterally. The anal triangle contains the ischioanal fossae; the urogenital triangle contains the perineal membrane and genital roots.
Overview
The perineum occupies the pelvic outlet below levator ani and coccygeus. A line between the ischial tuberosities divides its surface into urogenital and anal triangles. These regions contain the external genital and anal outlets together with their muscles, fascia, nerves and vessels.
Reference facts
- Boundaries
- Outlined by the pubic symphysis, ischiopubic rami, ischial tuberosities, sacrotuberous ligaments and coccyx; bounded superiorly by the pelvic diaphragm.
- Contents
- Urogenital triangle: genital roots, urethra, perineal muscles and vagina where present. Anal triangle: anal outlet, sphincter complex, ischioanal fat and lateral pudendal canals.
- Communications
- Communicates with pelvic outlet spaces and, by the lesser sciatic route, the gluteal region. Superficial fascial planes continue toward the lower abdominal wall.
Clinical correlation
The pudendal bundle passes around the ischial spine before reaching the perineum. Fascial continuity also allows some infections or traumatic fluid collections to extend between perineal, scrotal or vulval, and lower abdominal tissues.
Frequently asked questions
What are the boundaries of the perineum?
Outlined by the pubic symphysis, ischiopubic rami, ischial tuberosities, sacrotuberous ligaments and coccyx; bounded superiorly by the pelvic diaphragm.
What does the perineum contain?
Urogenital triangle: genital roots, urethra, perineal muscles and vagina where present. Anal triangle: anal outlet, sphincter complex, ischioanal fat and lateral pudendal canals.
What does the perineum communicate with?
Communicates with pelvic outlet spaces and, by the lesser sciatic route, the gluteal region. Superficial fascial planes continue toward the lower abdominal wall.