Puborectalis muscle
| Puborectalis muscle |
|---|
|
| M. levator ani |
| origin |
| Pubic bone |
| approach |
| Pubic bone |
| function |
| Sphincter of the rectum |
| Innervation |
| direct fibers from the sacral plexus |
The puborectalis muscle ("pubic bone-rectum muscle") is a striated muscle of the pelvic floor and part of the levator ani muscle .
It arises on the back of the pubic bone and forms a loop around the rectum at the transition to the anal canal , thereby causing the rectum to kink in the area of the anorectal line . It functions as the rectal sphincter and is therefore also known as the rectal sphincter muscle . During defecation, the muscle slackens so that the kink between the rectum and anal canal disappears and the column of feces can be transported backwards. The innervation takes place via the sacral plexus via nerve fibers from the S3 and S4 segments of the spinal cord .
Injury or loss of function leads to partial fecal incontinence . In the case of severe perineal tears , this muscle can partially maintain the stool's ability to hold the stool.
literature
- L. Richard Drake, Wayne Vogl, Adam WM Mitchell: Gray's Anatomy for students with StudentConsult access . Elsevier, Verlag Urban & Fischer 2007, ISBN 978-3-437-41231-8 , p. 410.