Its contraction is inhibited by parasympathetic fiber stimulation. During defecation, there is conscious relaxation of the puborectalis muscle, which creates a more open anorectal angle and allows for a straigther passage through the anal canal. Posteriorly, they are not attached to the coccyx, but are continuous with those of the opposite side behind the anal canal. The internal anal sphincter is an extension of the muscularis externa, and thus is smooth muscle purple innervated by enteric neurons found in the myenteric plexus. Retrieved from " https: The IRB-PX came from the superior aspect of the levator ani and ran into the anal canal on the anterolateral side. Atom, smallest unit into which matter can be divided without the release of electrically charged particles.
Inferior fascia Superior fascia.
External anal sphincter
Where would you find the cell body of a neuron innervating the internal anal sphincter? Colles' fascia in scrotum and penis: This page was last edited on 1 Octoberat Photosynthesis, the process by which green plants and certain other organisms transform light energy…. Its action is entirely involuntary, and it is in a state of continuous maximal contraction. Suspensory muscle Major duodenal papilla Minor duodenal papilla Duodenojejunal flexure Brunner's glands.