external anal sphincter

(redirected from Sphincter ani externus muscle)
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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.