Trotter J A, Purslow P P
Department of Anatomy, University of New Mexico School of Medicine, Albuquerque 87131.
J Morphol. 1992 May;212(2):109-22. doi: 10.1002/jmor.1052120203.
Many skeletal muscles, including the feline biceps femoris, are composed of short, tapered myofibers arranged in an overlapping longitudinal series. The endomysium of such muscles transfers tension between overlapping myofibers, and is thus an elastic element in series with them. The endomysium of the cat biceps femoris contains curvilinear collagen fibrils in an approximately isotropic (random) array. The collagen fibrils undergo only a modest reorientation as the myofibers shorten or lengthen within the physiological range. A geometrical model predicts no change in the thickness of the endomysium on changing muscle fiber length and quantifies the expected collagen fibril reorientation in the endomysium as a function of muscle extension. It is also demonstrated that a high proportion of the collagen fibrils will be curvilinear at all sarcomere lengths. The organization of endomysial collagen is appropriate for the transfer of loads between myofibers by means of shear.
许多骨骼肌，包括猫的股二头肌，是由短的、逐渐变细的肌纤维组成，这些肌纤维以重叠的纵向序列排列。这类肌肉的肌内膜在重叠的肌纤维之间传递张力，因此是与它们串联的弹性元件。猫股二头肌的肌内膜含有呈近似各向同性（随机）排列的曲线形胶原纤维。当肌纤维在生理范围内缩短或伸长时，胶原纤维仅发生适度的重新定向。一个几何模型预测，改变肌肉纤维长度时肌内膜厚度不会改变，并将肌内膜中预期的胶原纤维重新定向量化为肌肉伸展的函数。还证明在所有肌节长度下，很大比例的胶原纤维将呈曲线形。肌内膜胶原的组织方式适合通过剪切在肌纤维之间传递负荷。
