Rectal continence is mainly maintained by?

Ans. b (Puborectalis). (Ref. BDC 4th/Vol 2./pg. 383; Bailey and Love 25th/pg. 1241).RPC 4*/VQl2jpg>> 381........."Anorectal ring is a muscular ring present at the anorectal junction. It is formed by the fusion of the puborectalis, deep external sphincter and the internal sphincter. It is easily felt by finger in the anal canal. Surgical division of this ring results in rectal incontinence. The ring is less marked anteriorly where the fibers of the puborectalis are absent."PUBORECTALIS# It forms a sling around anorectal junction and is attached anteriorly to posterior aspect of pubis.# In resting state anorectal region is angled anteriorly at the level of puborectalis and contraction of puborectalis sling increases the angle, a vital part in maintenance of continence.# Contraction of the puborectalis fibers greatly assists the anal sphincters in maintaining continence under these conditions by pulling the anorectal junction upward and forward.# During the act of defecation however, the levator ani continues to support the pelvic viscera but the puborectalis fibers relax with the anal sphincters.# The most important part of the sphincteric mechanism of the anal canal is the anorectal ring. It consists of the deep part of the external sphincter, the internal sphincter, and the puborectalis part of the levator ani.# Surgical operations on the anal canal that result in damage to the anorectal ring will produce fecal incontinence# Normally, the anal canal is kept closed by the tone of the internal and external anal sphincters and the tone of the puborectalis part of the levator ani muscles.