Puborectalis muscle

Puborectalis muscle
The posterior aspect of the rectum exposed by removing the lower part of the sacrum and the coccyx. (Puborectalis not labeled, but levator ani labeled at bottom right, and sphincter ani ext labeled at bottom center.)
Left Levator ani from within. (Puborectalis not labeled, but 'levator ani' labeled at center, and anal canal labeled at bottom center.)
Latin musculus puborectalis
Gray's subject #119 424
Origin lower part of the pubic symphysis, superior fascia of the urogenital diaphragm
Insertion   
Artery
Nerve S3, S4. levator ani nerve [1]
Actions inhibit defecation

The fibers which form a sling for the rectum are named the Puborectalis or Sphincter recti.

They arise from the lower part of the pubic symphysis, and from the superior fascia of the urogenital diaphragm.

They meet with the corresponding fibers of the opposite side around the lower part of the rectum, and form for it a strong sling. Relaxation reduces the angle between rectum and anus, allowing defecation in conjunction with relaxation of the internal and external sphincters.

Puborectalis is part of the levator ani group of muscles.

References

  1. ^ Wallner C, Maas C, Dabhoiwala N, Lamers W, Deruiter M (2006). "Evidence for the innervation of the puborectalis muscle by the levator ani nerve.". Neurogastroenterol Motil 18 (12): 1121–2. doi:10.1111/j.1365-2982.2006.00846.x. PMID 17109696. 

External links