Anal triangle

The anal triangle is the posterior part of the perineum. It contains the anus in mammals.

Structure
The anal triangle can be defined either by its vertices or its sides.
 * Vertices
 * one vertex at the coccyx bone
 * the two ischial tuberosities of the pelvic bone
 * Sides
 * perineal membrane (posterior border of perineal membrane forms anterior border of anal triangle)
 * the two sacrotuberous ligaments

Contents
Some components of the anal triangle include:
 * Ischioanal fossa
 * Anococcygeal body
 * Sacrotuberous ligament
 * Sacrospinous ligament
 * Pudendal nerve
 * Internal pudendal artery and internal pudendal vein
 * Anal canal
 * Muscles
 * Sphincter ani externus muscle
 * Gluteus maximus muscle
 * Obturator internus muscle
 * Levator ani muscle
 * Coccygeus muscle