Rat extraocular muscle. 1. Three dimensional cytoarchitecture, component fibre populations and innervation.

摘要: Rat superior oblique extraocular muscle was examined in serial sections by light and electron microscopy. By such analysis, it possible to discriminate single versus multiply innervated fibres, characteristics of the internal structure topographical distribution respective fibre populations within muscle. The observed consist two distinguishable portions; one portion originated proximally other distally after passing through trochlea tendon. Seven morphologically distinct were discernible. Four populations, three singly population, localised global region; these differed terms diameter, mitochondrial richness, development sarcoplasmic reticulum myofibrillar size. orbital surface layer contained populations; all exhibited systematic morphological variability. fibres displayed multiple, relatively superficial, neuromuscular junctions along their length, as well end plate-like which apparently confined region innervation band, thus suggesting polyneuronal innervation. In latter region, features characteristic "twitch' fibres; away from this cells appeared have typical "tonic' fibres. contrast, constant diameter form only superficial junctions.