Development of the masseter muscle and oral behavior in the pig.
Development of the masseter muscle and oral behavior in the pig.
复制标题
猪咬肌的发育和口腔行为。
DOI：
10.1002/jez.1402370206
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发表时间：
1986
期刊：
影响因子：
--
通讯作者：
Wineski,LE
中科院分区：
文献类型：
--
作者：
Herring,SW;Wineski,LE
在咀嚼过程中，成年猪咬肌以复杂的模式收缩，包括从腹侧角到背侧角移动的肌电图（EMG）活动波。本研究是为了确定这种收缩模式的个体发生。对胎猪、幼猪和幼猪的咬肌进行了解剖学测量。当仔猪和幼猪哺乳、饮水和咀嚼食物和非食物物体时，记录咬肌不同部位的EMG活动沿着口腔运动。肌纤维和腱性腱膜的基本排列在各年龄段是相同的。最长和最垂直的纤维被发现吻侧和腹侧，而最短和最水平的纤维被发现尾侧和背侧。肌束长度随年龄增长而下降，相对于肌肉重量。随着年龄的增长，肌肉不同部位之间的长度差异增大。胎儿咬肌的方向通常比老年动物的咬肌更水平，除了背尾侧角，通常是最水平的部分，在胎儿中没有发育。婴儿咬肌内的收缩模式没有老年动物复杂;只有背尾侧角是不同的。肌内活动差异的进一步发展可能与咬肌解剖结构的复杂性增加有关，这增强了咬肌的功能。
During mastication the adult pig masseter contracts with a complex pattern involving a wave of electromyographic (EMG) activity moving from the ventro‐rostral corner to the dorso‐caudal corner. The present study was undertaken to ascertain the ontogeny of that contraction pattern. Anatomical measurements were made on masseters from fetal, infant, and juvenile pigs. EMG activity from different parts of the masseter was recorded along with oral movements in infant and juvenile pigs as they suckled, drank, and chewed on food and non‐food objects. The basic arrangement of muscle fibers and tendinous aponeuroses was found to be the same in all ages. The longest and most vertical fibers were found rostrally and ventrally, whereas the shortest and most horizontal fibers were found caudally and dorsally. The length of fasciculi decreased with age, relative to muscle weight. Variance in length among different parts of the muscle increased with age. Fetal masseters were oriented generally more horizontally than the masseters of older animals, except that the dorso‐caudal corner, usually the most horizontal portion, is not developed in fetuses. The contraction patterns within the infant masseter were less complex than those of older animals; only the dorso‐caudal corner was distinct. The further development of intramuscular differences in activity may be associated with the increasing anatomical complexity of the masseter, which augments its functional capabilities.