Puborectalis muscle

From Wikipedia, the free encyclopedia

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 symphysis pubis, superior fascia of the urogenital diaphragm
Insertion
Artery:
Nerve:	S3, S4. levator ani nerve [1]
Action:	inhibit defecation
Dorlands /Elsevier	m_22/12550328

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

They arise from the lower part of the symphysis pubis, 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.

[edit] 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. 

[edit] External links

• LUC pubr
• Puborectalis+muscle at eMedicine Dictionary
• Norman/Georgetown pelvis
• SUNY Labs 43:16-0200 - "The Female Pelvis: Muscles of the Pelvic Diaphragm"
• SUNY Labs 44:12-0200 - "The Male Pelvis: Muscles of the Pelvic Diaphragm"

v • d • e List of muscles of torso BACK splenius (capitis, cervicis) - erector spinae (iliocostalis, longissimus, spinalis) - latissimus dorsi transversospinales: (semispinalis dorsi, semispinalis cervicis, semispinalis capitis, multifidus, rotatores) - interspinales - intertransversarii SUBOCCIPITAL rectus capitis posterior (major, minor) - obliquus capitis (inferior, superior) CHEST intercostales (external, internal, innermost) - subcostales - transversus thoracis - levatores costarum - serratus posterior (inferior, superior) - diaphragm ABDOMEN anterior/lateral wall: obliques (external, internal) - transversus abdominis - rectus abdominis - pyramidalis posterior wall: quadratus lumborum - psoas major/psoas minor - iliacus cremaster PELVIS/FLOOR levator ani (iliococcygeus, pubococcygeus, puborectalis) - coccygeus PERINEUM anal triangle: sphincter ani (externus, internus) superficial perineal pouch (superficial transverse perineal, bulbospongiosus, ischiocavernosus) deep perineal pouch (deep transverse perineal, sphincter urethrae membranaceae)