人颞肌和咬肌肌梭分布的体视学研究

目的 研究人咬肌和颞肌的肌梭形态和分布特征，探讨其在咀嚼活动和下颌位置的维持和调节中所起的神经生物学作用。方法 对5具尸体的双侧人咬肌和颞肌的肌梭作形态学观察，再用图像分析仪测量肌梭的长度和直径，并计算肌梭数、肌梭密度和梭内肌纤维数。结果 咬肌和颞肌肌梭分布呈不均质性，多成簇分布于特定的区域，且形态多样，以单个体和联合体形式存在。咬肌肌梭大多位于深层，而浅层仅在靠近肌腹中央附近发现有较少量的肌梭；颞肌肌梭密集分布于前份纤维靠近喙突处，而在颞肌的后缘以及远端缺乏肌梭的分布。对咬肌浅、深两层和颞肌前、后两部的肌梭密度进行比较，显示咬肌深层肌梭密度最高，颞肌前部次之，颞肌后部肌梭密度最低。结论 咬肌和颞肌的肌梭分布呈不均质性，咬肌深层和颞肌前部肌梭密度高。咬肌深层和颞肌前部在下颌位置的维持和调节中起主要作用。

Stereology Investigation of Muscle Spindles in Human Masseter and Temporalis Muscle

Objective To find out the characteristic topographic distribution of the muscle spindles in human masseter and temporal muscle, and to clarify the neurobiology roles of masficatory muscles during chew and adjusting mandibular position. Methods The muscle spindles of masseter and temporal muscle on both sides of 5 human corpses fixed in formalin for more than 1 year were observed and quantitativdy analyzed by picture analysis equip-- menL Results The muscle spindles were maldistributed and spindles were commonly clustered in some individual portions, and the muscle spindle figures were diversiform, which were predominantly composed of the spindle simple and spindle complexes, the masseter spindles of the deep portion were obviously more than that of the supodicial. Spindles of temporal muscle were concentrated in the anterior approach to the coracoid. Conclusion The distribution of muscle spindles in the masseter and temporal muscle is heterogeneous, spindle density in the deep portion of masseter and the anterior of temporolismuscle is greater than others. The deep of masseter and the anterior of ternpond muscle play an important part in maintaining mandibular position and balance.