The anal canal is located within the anal triangle of the perineum between the right and left ischioanal fossae. It is the final segment of the gastrointestinal tract, around 4cm in length. The canal begins as a continuation of the rectum , and passes inferoposteriorly to terminate at the anus. Except during defecation, the anal canal is collapsed by the internal and external anal sphincters to prevent the passage of faecal material. It is formed by the fusion of the internal anal sphincter, external anal sphincter and puborectalis muscle, and is palpable on digital rectal examination.
Anal canal , the terminal portion of the digestive tract , distinguished from the rectum because of the transition of its internal surface from a mucous membrane layer endodermal to one of skinlike tissue ectodermal. The anal canal is 2. The canal is divided into three areas: the upper part, with longitudinal folds called rectal columns; the lower portion, with internal and external constrictive muscles sphincters to control evacuation of feces ; and the anal opening itself. The anal canal connects with the rectum at the point where it passes through a muscular pelvic diaphragm.
Sign up. Illustrated anatomical parts with images from e-Anatomy and descriptions of anatomical structures. Its mucosa is lined by simple columnar epithelium.
The anal valves or valves of Ball are small valve-like folds at the lower ends of the anal sinuses in the rectum. The anal valves join together the lower ends of the anal columns. The anal sinuses are located between them.