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...

of the anal canal and lower part of the rectum Median sagittal section of male pelvis Median sagittal section of female pelvis Anal columns Anal sinuses...

conditions, including cancer (see anal cancer). With anal sex, the anus can play a role in sexuality. Attitudes toward anal sex vary, and it is illegal in...

anal sinus (rectal sinus) is a furrow formed between any two adjacent anal columns of the anal canal. An anal sinus is limited inferiorly by an anal valve...

is followed by the anal canal, which is about 4 centimetres (1.6 in) long, before the gastrointestinal tract terminates at the anal verge. The word rectum...

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...

anal sphincter is far more substantial than the internal anal sphincter. The proximal portion of external anal sphincter overlaps the internal anal sphincter...

The internal anal sphincter, IAS, or sphincter ani internus is a ring of smooth muscle that surrounds about 2.5–4.0 cm of the anal canal. It is about...

mucosa Penile mucosa Respiratory mucosa Vaginal mucosa Frenulum of tongue Anal canal Conjunctiva Developmentally, the majority of mucous membranes are of...

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...