Wikipedia
The anal canal is the terminal part of the large intestine. It is situated between the rectum and anus, below the level of the pelvic diaphragm. It lies in the anal triangle of perineum in between the right and left ischioanal fossa.
The anal canal is divided into three parts. The zona columnaris is the upper half of the canal and is lined by simple columnar epithelium. The lower half of the anal canal, below the pectinate line, is divided into two zones separated by Hilton's white line. The two parts are the zona hemorrhagica and zona cutanea, lined by stratified squamous non-keratinized and stratified squamous keratinized, respectively.
In humans it is approximately 2.5 to 4 cm long, extending 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.
It is differentiated from the rectum by the transition of the internal surface from endodermal to skinlike ectodermal tissue.
Usage examples of "anal canal".
If heart palpitations occur during coition, interrupt at once and think about parasitic worms infesting your anal canal.
The girl's bung was so stretched by the ivory dildo that she did not flinch until Uncle Ma, wild with lust, began to drive himself deeply into her anal canal.
The first time I tried it, I turned the handle too far and reversed my anal canal while striking my head on the deck above.
Whoever invented these things, by the way, should have them stuffed up his anal canal until the strings in the back come out his ears.
I asked them to rest a few moments and enjoy the sensation of feeling where we were, our pricks throbbing against each other in a most delicious manner, with only the thin membrane of the anal canal between them.
I know for a fact that a cherry bomb exploding two feet into her anal canal wouldn't even make her blink.