Dual innervation of the iris sphincter muscle of the albino guinea pig.
D000818:Animals; D001341:Autonomic Nervous System; D001369:Axons; D003594:Cytoplasmic Granules; D006168:Guinea Pigs; D007498:Iris / Q000294:innervation*; D008854:Microscopy, Electron; D009130:Muscle, Smooth / Q000166:cytology / Q000294:innervation*; D013564:Sympathetic Nervous System