high density of innervation and vascularization , wide range of striated muscle fibre diameters , presence of lipid vacuoles and of large clusters of mitochondria in the striated fibres , occurrence of peripheral couplings of the sarcoplasmic reticulum , and presence of numerous fibroblast processes in the interstices between fibres , characterize the sphincter pupillae of the mature iris .
C0229189
sphincter pupillae
C0022077
iris