MaleMusFIG 32: Anal depressor muscle.

A. Low power electron micrograph featuring anal depressor and gap junctions to the protractor muscles, transverse view. (Image source: N2Y [MRC] 37.)
B. Detailed view of boxed region in A showing gap junctions. (PAG) Pre-anal ganglion; (v/dspL/R) ventral and dorsal spicule protractors; (adp) anal depressor.