The perineum is diamond shaped space lies between the symphysis pubis and coccyx, made up of 2 triangular spaces with the common base in between them. It can refer to the superficial structures or it can be used to include both superficial and deep structures. A line is drawn across the ischial tuberosities divides the space into two triangles anterior urogenital triangle or the posterior anal triangle.
-The posterior anal triangle containing the anal canal with the sphincter.
-The anatomical boundaries of the perineum are the pubic arch and the arcuate ligament of the pubis anteriorly, the coccyx posteriorly, the inferior rami of the pubis, sacral tuberosities and the sacrotuberous ligament laterally.
-The region of the perineum is separated by the pelvic diaphragm (muscles with the covering fascia). These are pubococcygeus, iliococcygeus, and ischiococcygeus combinedly known as levator ani. The perineal body is a pyramidal fibromuscular mass in the middle line of the perineum at the junction between the urogenital triangle and the anal triangle.