Circumscript Sphincter: A sphincter muscle forming a sharply marked cord histologically shown projecting into the body cavity, attached only along a narrow line to the column; its processes radiate outward from a narrow region of attachment or from a primary lamella of which they are secondary offshoots (Stephenson, 1928; p. 9). In other words, there is one large muscle fiber emanating from the main longitudinal muscle sheet, and all of the other muscle fibers are stemming from it.

Circumscript Sphincters are either Palmate or Pinnate.

See Also: Sphincter or Diffuse sphincter