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
Additional images
See also
- Perineum
- Urogenital triangle
References
External links
- Anatomy photo:41:01-0202 at the SUNY Downstate Medical Center - "The Female Perineum: Boundaries of the Female Perineum"
- perineum at The Anatomy Lesson by Wesley Norman (Georgetown University) (perineumboundaries)
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