extrinsic sphincter

ex·trin·sic sphinc·ter

a sphincter provided by circular muscular fibers extraneous to the organ.

ex·trin·sic sphinc·ter

(eks-trin'zik sfingk'tĕr)
A sphincter provided by circular muscular fibers extraneous to the organ.
References in periodicals archive ?
In addition, the bottom of your diaphragm sits flush with the LES and acts as an extrinsic sphincter or valve," Dr.