An electromyographic study of the function of the jaw adducting muscles in Varanus exanthematicus (varanidae)
An electromyographic study of the function of the jaw adducting muscles in Varanus exanthematicus (varanidae)
复制标题
急疹巨蜥（巨蜥科）下颌内收肌功能的肌电图研究
DOI：
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发表时间：
1982
影响因子：
1.5
通讯作者：
Kathleen K. Smith
中科院分区：
文献类型：
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作者：
Kathleen K. Smith
应用放射电影摄影和肌电图技术，研究了巨蜥颅骨主要特征在摄食过程中的功能。在进食的最初阶段，巨蜥在口中抓住猎物并定位，没有咀嚼，撕裂猎物或杀死咬。摄入是通过一个高度定型的运动，惯性进食。舌头在食物运输中不起作用。一旦猎物进入咽部，舌骨器就会将猎物挤压到食道和胃中。在猎物定向和惯性摄食过程中，下颌内收肌的活动有显著的不同。在捕食取向，收肌肌肉系统是活跃的，在很长一段时间，肌间分化和单边活动是常见的。在这些阶段，肌肉组织产生的力量对抗牙齿之间的猎物的阻力。在惯性进食中，颌部肌肉组织的功能是在阻力很小的情况下迅速闭合颌部。肌内分化的一致模式是存在的，与肌肉组织的一些部分是活跃的，在两个下巴打开和关闭。下颌外收肌和翼肌的活动难以区分。在惯性进食过程中，既没有观察到中动运动，也没有观察到亚动运动;在动力阶段，颅间运动的分辨率不太确定。在惯性进给中，方头在钳口张开和闭合过程中发生运动。但其运动与腭上颌段的运动无明显联系。这些数据在三个方面进行了讨论：颅运动，肌内分化，和整个肌肉的力学。
The function of major features of the skull of Varanus exanthematicus during feeding was examined using cineradiography and electromyography. During the initial stages of feeding, Varanus grabs and orients a prey item in the mouth with no mastication, tearing of the prey, or killing bite. Ingestion is through a highly stereotyped movement, inertial feeding. The tongue plays no role in food transport. Once the prey is in the pharyngeal region, the hyoid apparatus squeezes the prey into the esophagus and stomach. Activity of jaw adducting muscles during prey orientation and inertial feeding is strikingly different. In prey orientation, the adductor musculature is active over long periods, and intermuscular differentiation and unilateral activity are common. During these phases the musculature is producing force against the resistance of the prey item held between the teeth. In inertial feeding, the jaw musculature functions to close the jaws rapidly against little resistance. A consistent pattern of intramuscular differentiation is present, with some portions of the musculature being active during both jaw opening and closing. Activity of the Mm. adductor mandibulae externus and pterygoideus is indistinguishable. Neither meso‐ nor metakinetic movement was observed during inertial feeding; resolution of interacranial movement was less certain during power phases. The quadrate moved during jaw opening and closing in inertial feeding. However, its movement was not linked with that of the palatomaxillary segment. These data are discussed in three contexts: cranial kinesis, intramuscular differentiation, and the mechanics of whole muscles.