title: The sphincter pupillae of the guinea-pig: structure of muscle cells, intercellular relations and density of innervation.
mesh_terms: D000818:Animals; D006168:Guinea Pigs / Q000033:anatomy & histology*; D007498:Iris / Q000166:cytology* / Q000294:innervation / Q000648:ultrastructure; D008297:Male; D008854:Microscopy, Electron; D009130:Muscle, Smooth / Q000166:cytology* / Q000294:innervation / Q000648:ultrastructure; D009210:Myofibrils / Q000648:ultrastructure; D012519:Sarcoplasmic Reticulum / Q000648:ultrastructure