external anal sphincter
Definition: a fusiform ring of striated muscular fibers surrounding the anus, attached posteriorly to the coccyx and anteriorly to the central tendon of the perineum; it is subdivided, often indistinctly, into a subcutaneous part, a superficial part, and a deep part for descriptive purposes.
Synonym(s): musculus sphincter ani externusTA, external sphincter muscle of anus
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Examples: glitazone, GI cocktail, etc.