title: Fine structure of elasmobranch iris muscle and associated nervous structures.
mesh_terms: D000818:Animals; D005399:Fishes / Q000033:anatomy & histology*; D007498:Iris / Q000166:cytology* / Q000294:innervation; D008854:Microscopy, Electron; D009119:Muscle Contraction; D009130:Muscle, Smooth / Q000294:innervation*; D009411:Nerve Endings / Q000166:cytology; D009469:Neuromuscular Junction / Q000166:cytology; D011680:Pupil; D012754:Sharks; D009435:Synaptic Transmission; D013572:Synaptic Vesicles