Ruskell G L
J Neurocytol. 1978 Dec;7(6):693-708. doi: 10.1007/BF01205145.
Many of the myelinated nerve fibres of the distal myotendinous region of rectus muscles terminate on muscle fibre tips. The terminal expansions contain aggregated, small clear vesicles and mitochondria. Neuromuscular clefts at the contacts measure 20--40 nm and are uninterrupted by a basal lamina; the sarcoplasm opposite the contacts is unmodified. Some terminals invaginate the muscle fibre tips and others contact the sides of processes formed by splitting of the tips. The muscle fibre termination, its tendon and the nerve fibre branches are encapsulated to form an end-organ averaging 125 micrometer in length and described as a myotendinous cylinder. Approximately 350 innervated myotendinous cylinders were estimated to be present in the horizontal recti with rather fewer in the vertical rectus muscles. Many of them occur shortly before the main myotendinous junction. All muscle fibres contributing to myotendinous cylinders were identified as the compact, felderstruktur, multi-innervated variety with directly apposed myofibrils that are known to be non-twitch fibres. All felderstruktur fibre terminations examined were encapsulated but 19% of them were not innervated. The nerve terminals of myotendinous cylinders are similar to those described by Dogiel (1906) as palisade endings and it is argued that they meet the morphological criteria of sensory neuromuscular endings. Their disposition suggests a capacity to monitor felderstruktur muscle fibre contraction.
直肌远端肌腱区域的许多有髓神经纤维终止于肌纤维末端。终末膨大含有聚集的小清亮囊泡和线粒体。连接处的神经肌肉裂隙宽20 - 40纳米，无基膜中断；连接处相对的肌浆未发生改变。一些终末向肌纤维末端内陷，另一些则与末端分裂形成的突起侧面接触。肌纤维末端、其肌腱和神经纤维分支被包裹形成一个平均长度为125微米的终末器官，称为肌腱圆柱体。据估计，水平直肌中约有350个有神经支配的肌腱圆柱体，垂直直肌中的数量相对较少。它们中的许多在主要肌腱连接处之前不久出现。所有参与肌腱圆柱体形成的肌纤维均被鉴定为紧密的、呈编织状结构、多神经支配的类型，其肌原纤维直接并列，已知为非收缩性纤维。所有检查的编织状结构纤维末端均被包裹，但其中19%没有神经支配。肌腱圆柱体的神经末梢与多吉尔（1906年）描述的栅栏状末梢相似，有人认为它们符合感觉神经肌肉末梢的形态学标准。它们的分布表明其具有监测编织状结构肌纤维收缩的能力。
