Urogenital Triangle
Definition
o Perineum is the surface region between the pubic symphysis and the coccyx.
o The perineum is studied in two parts the urogenital triangle and anal triangle
o Inferior to the pelvic diaphragm and between the legs.
o But at times perineum is defined in females as the area extending from the fourchette (fusion of the labia minora posteriorly) to the anal canal.
Features
o Roughly triangular
o Consists of connective tissue, muscle and fat.
o It gives attachment to the muscles of the pelvic floor (levator ani and coccygeus)
The Two Parts
o A line joining the anterior parts of the ischial tuberosities divides the perineum into a large posterior anal triangle and a smaller anterior urogenital triangle.
o The anal triangle contains the anal canal and the ischiorectal fossae with their contents.
o Lying in front of the anal canal is a fibro-muscular mass of tissue called the perineal body
o It is fixed to the pelvic floor
o It forms part of the pelvic floor
The contents of the urogenital triangle
o differ in the male and the female
In the male :
o the triangle contains perineal membrane (also called the triangular ligament)
o the penis and the penile musculature are attached to the perineal membrane
o the scrotum hangs below the perineal membrane
o above the perineal membrane lies the membranous urethra the sphincter urethrae and the apex of the prostate.
o the perineal membrane is pierced by the urethra and by foramina for nerves and vessels.
o It is attached to the ischio-pubic rami
o from the subpubic angle back to the level of the anterior part of the ischial tuberosities
o The urogenital triangle contains the external genitalia and the urethra.
o The space containing these structures is called the superficial perineal pouch.
