the smooth muscle ring, formed by an increase of the circular muscle fibers of the rectum, situated at the upper end of the anal canal, internal to the outer voluntary external anal sphincter [ http://www.informatics.jax.org/accession/anna MP:0009055 ]

Synonyms: circular muscle layer of anal canal circular layer of anal muscularis externa circular layer of muscularis externa of anal canal circular layer of muscularis propria of anal canal

This is just here as a test because I lose it

Term information

Subsets

uberon_slim, pheno_slim

depicted by

http://upload.wikimedia.org/wikipedia/commons/e/e9/Gray1079.png

id

UBERON:0001244