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Anal Valves
An anal valve is a small horizontal fold uniting the inferior ends of any two adjacent anal columns of the anal canal. An anal valve forms the inferior boundary of an anal sinus. The anal valves demarcate the level of the pectinate line The pectinate line (dentate line) is a line which divides the upper two-thirds and lower third of the anal canal. Developmentally, this line represents the hindgut- proctodeum junction. It is an important anatomical landmark in humans, and fo .... References External links * — "The Female Pelvis: The Rectum" Digestive system {{digestive-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rectum
The rectum (: rectums or recta) is the final straight portion of the large intestine in humans and some other mammals, and the gut in others. Before expulsion through the anus or cloaca, the rectum stores the feces temporarily. The adult human rectum is about long, and begins at the rectosigmoid junction (the end of the sigmoid colon) at the level of the third sacral vertebra or the sacral promontory depending upon what definition is used. Its diameter is similar to that of the sigmoid colon at its commencement, but it is dilated near its termination, forming the rectal ampulla. It terminates at the level of the anorectal ring (the level of the puborectalis sling) or the dentate line, again depending upon which definition is used. In humans, the rectum is followed by the anal canal, which is about long, before the gastrointestinal tract terminates at the anal verge. The word rectum comes from the Latin '' rēctum intestīnum'', meaning ''straight intestine''. Struc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anal Columns
Anal columns (Columns of Morgagni or less commonly Morgagni's columns) are a number of vertical folds, produced by an infolding of the mucous membrane and some of the muscular tissue in the upper half of the lumen of the anal canal. They are named after Giovanni Battista Morgagni Giovanni Battista Morgagni (25 February 1682 – 6 December 1771) was an Italian anatomy, anatomist, generally regarded as the father of modern anatomical pathology, who taught thousands of medical students from many countries during his 56 year ..., who has several other eponyms named after him. References External links * — "The Female Pelvis: The Rectum" * () Digestive system {{digestive-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anal Canal
The anal canal is the part that connects the rectum to the anus, located below the level of the pelvic diaphragm. It is located within the anal triangle of the perineum, between the right and left ischioanal fossa. As the final functional segment of the bowel, it functions to regulate release of excrement by two muscular sphincter complexes. The anus is the aperture at the terminal portion of the anal canal. Structure In humans, the anal canal is approximately long, from the anorectal junction to the anus. It is directed downwards and backwards. It is surrounded by inner involuntary and outer voluntary sphincters which keep the lumen closed in the form of an anteroposterior slit. The canal is differentiated from the rectum by a transition along the internal surface from endodermal to skin-like ectodermal tissue. The anal canal is traditionally divided into two segments, upper and lower, separated by the pectinate line (also known as the dentate line): * upper zo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anal Sinuses
An anal sinus (rectal sinus) is a furrow formed between any two adjacent anal columns of the anal canal The anal canal is the part that connects the rectum to the anus, located below the level of the pelvic diaphragm. It is located within the anal triangle of the perineum, between the right and left ischioanal fossa. As the final functional s .... An anal sinus is limited inferiorly by an anal valve (which unites the inferior ends of a pair of adjacent anal columns). The anal glands open into the anal sinuses. References External links * — "The Female Pelvis: The Rectum" * () Digestive system {{digestive-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pectinate Line
The pectinate line (dentate line) is a line which divides the upper two-thirds and lower third of the anal canal. Developmentally, this line represents the hindgut- proctodeum junction. It is an important anatomical landmark in humans, and forms the boundary between the anal canal and the rectum according to the anatomic definition. Colorectal surgeons instead define the anal canal as the zone from the anal verge to the anorectal ring (palpable structure formed by the external anal sphincter and the puborectalis muscle The levator ani is a broad, thin muscle group, situated on either side of the pelvis. It is formed from three muscle components: the pubococcygeus, the iliococcygeus, and the puborectalis. It is attached to the inner surface of each side of the ...). Several distinctions can be made based upon the location of a structure relative to the pectinate line: Additional images File:Rectoanal jxn.JPG, Microscopic cross section of the anorectal junction File:A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
