external anal sphincter


ex·ter·nal a·nal sphinc·ter

[TA] 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 externus [TA], external sphincter muscle of anus