The Perineum
The perineum is the shallow compartment at the inferior end of the pelvic outlet. It is bounded by the pelvic outlet and divided by a transverse line into two triangular regions.
Triangles of the Perineum
| Triangle | Key Structures |
|---|---|
| Urogenital (UG) Triangle | External genitalia, urethra, and perineal pouches. |
| Anal Triangle | Anal canal, anal sphincters, and ischio-anal fossae. |
Perineal Body
Located at the center of the perineum between the two triangles, the perineal body is a pyramidal fibromuscular mass. It serves as the attachment point for several muscles, including the bulbospongiosus, external anal sphincter, and superficial/deep transverse perineal muscles.
High-Yield Exam Pearl:
The ischiorectal (ischio-anal) fossa is a fat-filled space lateral to the anal canal. It is clinically important because infections here can easily form perianal abscesses, which can track through the perineal fascia and spread rapidly.