The anal opening is keratinized skin that has several folds while contracted. An endoscopy is a procedure where a doctor uses an endoscope — a small, flexible tube with a camera and light — to examine areas inside the body. Retrieved September 17, Nerve responses from the rectum cause the internal sphincter to relax while the external one contracts; shortly thereafter the external sphincter also relaxes and allows fecal discharge. Retrieved September 15, However, it becomes larger near the anus, where it forms the rectal ampulla. Sphincters upper lower glands.
Anal canalthe terminal portion of the digestive tractdistinguished from the rectum because of the transition of its internal surface from a mucous membrane layer endodermal to one of skinlike tissue ectodermal.
13 Fundamental Facts About the Anus
The anus is surrounded in its length by folds called anal valves, which converge at a line known as the pectinate line. When the storage site becomes full, the intrarectal pressure causes the anal canal walls to dilate and expand. Yet, I still hit 'save'. Check out the reddiquette page for more info - violations of any of those of clauses may result in a ban without warning. Contractions of abdominal and pelvic floor muscles can create intra-abdominal pressure which further increases intra-rectal pressure.