part of muscle invertebrate muscular system enteric muscle 2010-10-12T10:40:41Z BTO:0004878 BrendaTissueOBO Muscle cells of the posterior gut and rectum. There are four specialized muscle cells in this region that operate in the defecation cycle; the L/R stomatointestinal muscles (also called the intestinal muscles) , the anal sphincter muscle (also called the anal dilator or rectal muscle) and the anal depressor muscle (also called the depressor ani muscle). These three sets of muscles are jointly called enteric muscles and each send an arm to the DVB neuron along dorsal surface of the preanal ganglion. mgr