• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>American Zoologist >Intrinsic mechanics and control of fast cranio-cervical movements in aquatic feeding turtles
【24h】

Intrinsic mechanics and control of fast cranio-cervical movements in aquatic feeding turtles

机译：水生乌龟的内在力学和快速颅颈运动的控制

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

SYNOPSIS. Aquatic feeding strikes on agile prey in snake-necked turtles involve fast neck extension, bucco-pharyngo-oesophageal expansion, and head retraction. The ultimate, rectilinear acceleration of the head towards the prey requires complex vertebral rotations, that vary widely from strike to strike. This poses complex motor control issues for the numerous intrinsic neck-muscles, which are the sole neck extensors. Mathematical modelling reveals that extensor activity might be superfluous for this phase of the strike. The ultimate acceleration of the head at the end of the strike always coincides with forceful oropharyngeal expansion. The momentum of the induced flow of water is sufficient to pull the head (and the neck) straight towards the prey. This buccal expansion proceeds identically to that observed in primary aquatic feeders: a rostro-caudal expansion sequence characterized by an optimal timing of the functional components supporting the expansion wave. Yet distinct structural solutions, both at the skeletal, and muscular level, are involved. This points towards prominent hydrodynamic constraints. Head and neck are retracted by extrinsic neck muscles. Given the high number of degrees of freedom, this musculo-skeletal system is obviously under-determined, which compromises control. We propose that erroneous folding of the neck (i.e., diverging from the highly persistent retracted configuration) might be avoided through the presence of a subtle click system at the level of the joint between cervical vertebrae 5 and 6.
机译：概要。蛇颈龟对敏捷猎物的水生食性攻击包括快速的颈部伸展，颊咽-食管扩张和头部缩回。头部朝猎物的最终直线加速需要复杂的椎骨旋转，每次旋转之间差异很大。这给众多固有的颈部肌肉带来了复杂的运动控制问题，这些肌肉是唯一的颈部伸肌。数学模型表明，在罢工的这一阶段，伸肌活动可能是多余的。打击结束时头部的最终加速度始终与口咽部的有力扩张相吻合。感应水流的动量足以将头（和脖子）拉向猎物。这种颊部扩张的过程与在初级水生饲养器中观察到的过程相同：rostro-caudal扩张序列，其特征在于支持扩张波的功能组件的最佳时机。但是，涉及骨骼和肌肉方面的独特结构解决方案。这指向显着的水动力约束。头部和颈部因颈部外在肌肉收缩。鉴于自由度很高，这个肌肉骨骼系统显然是不确定的，这不利于控制。我们建议可以通过在颈椎5和6之间的关节处存在细微的咔嗒声系统来避免颈部的错误折叠（即与高度持久的缩回结构分开）。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号