THE ANSA CERVICALIS AND THE INFRAHYOID MUSCLES OF THE RAT .1. ANATOMY-DISTRIBUTION, NUMBER AND DIAMETER OF FIBER TYPES MOTOR UNITS
THE ANSA CERVICALIS AND THE INFRAHYOID MUSCLES OF THE RAT .1. ANATOMY-DISTRIBUTION, NUMBER AND DIAMETER OF FIBER TYPES MOTOR UNITS
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DOI：
10.1007/bf00299254
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发表时间：
1980-01-01
期刊：
影响因子：
--
通讯作者：
ZENKER, W
中科院分区：
文献类型：
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作者：
MUNTENER, M;GOTTSCHALL, J;ZENKER, W
颈袢和舌骨下肌（胸骨舌骨肌、胸骨甲状肌、肩胛舌骨肌）的地形解剖学以及定性和定量的肌纤维组成已在大鼠中进行了研究。袢由上根和下根组成，分别接收来自舌下神经和 C 1-3 的纤维。不断发现两个主要分支，一个水平分支，离开上根部，一个下降分支，离开顶点，而较小的分支表现出相当大的变异性。胸骨舌骨肌由上腹部和下腹部组成。腱交叉处是胸骨甲状肌的起点。不同类型的纤维均匀分布在胸骨舌骨肌（两侧腹部）、胸骨甲状肌和肩胛舌骨肌（缺乏 I 型 (β) 纤维）中。胸骨舌骨肌显示少量属于 I 型纤维的纤维，这些纤维经常出现在下腹部，但仅偶尔出现在上腹部。这些肌纤维可能不属于单个运动单位。与 IIA 型 (α) 和 I 型纤维相反，IIB (αβ) 型纤维的直径变化很大。肌梭经常出现在舌骨下肌中，其中胸甲肌含有最多数量的肌梭。不同肌肉中运动单位的平均大小为 77 至 86 个。
The topographical anatomy of the ansa cervicalis and the infrahyoid muscles (sternohyoid, sternothyroid, omohyoid) as well as the qualitative and quantitative muscle fiber composition have been studied in the rat.The ansa consists of a superior and an inferior radix receiving fibers from the hypoglossal nerve and from C 1–3, respectively. Two main branches, a horizontal one, leaving the superior radix and a descending one, leaving the vertex were found constantly, while the smaller branches exhibit a considerable variability.The sternohyoid muscle is built up of a superior and an inferior belly The tendinous intersection serves as origin for the sternothyroid muscle. The different fiber types are evenly distributed in the sternohyoid (both bellies), the sternothyroid, and the omohyoid muscle (lacking type I (β) fibers).The sternohyoid muscle displays a small number of fibers classified as type I fibers which are regularly found in the inferior but only sporadically in the superior belly. These muscle fibers probably do not belong to a single motor unit.In contrast to the type IIA (α) and the type I fibers the type IIB (αβ) fibers display a considerably varying diameter. Muscle spindles were regularly found in the infrahyoid muscles, the sternothyroid muscle containing proportionally the greatest number of spindles.The mean size of the motor units ranges from 77 to 86 in the different muscles.