Perineum - LO 2
2. Diagram the boundaries of the perineum, and understand the location and function of the perineal body.
The perineum is the region of the pelvis superficial to the pelvic floor, and may be best conceptualized as a diamond-shaped structure consisting of two non-coplanar triangles: the urogenital triangle and the anal triangle.
The urogenital triangle of the perineum consist of the following layers (superficial-to-deep):
Skin
Subcutaneous
Superficial fatty (Camper’s) fascia
Deep membranous (Colles’) fascia
This layer is continuous with the Scarpa’s fascia of the abdomen
Superficial perineal space (pouch)
Ischiocavernosus mm. & Crura of clitoris/penis
Bulbospongiosus mm. & Vestibular bulbs/bulb of the penis
Greater vestibular (Bartholin’s) glands
Superficial transverse perineal mm.
Perineal membrane
Deep perineal space (pouch)
Compressor urethrae (external urethral sphincter)
Deep transverse perineal mm.
Bulbo-urethral (Cowper’s) glands
Levator ani m. & perineal body
The anal triangle contains the anal canal and anal sphincters, and the ischio-anal (ischiorectal) fossae with pudendal canals.
The perineal body, a fibromuscular mass, sits on the midline between the urogenital and anal triangles, at the level of the muscles within the superficial perineal space and external anal sphincter. It may be palpated through the skin, but it may only be seen upon dissection into the superficial space of the urogenital triangle and anal triangle.