Shimokawa Takashi, Akita Keiichi, Sato Tatsuo, Ru Fei, Yi Shuang-Qin, Tanaka Shigenori
Department of Anatomy and Neuroembryology, Kanazawa University, Japan.
Okajimas Folia Anat Jpn. 2002 May;79(1):1-10. doi: 10.2535/ofaj.79.1.
In the present study, we investigated the structure and nerve innervation of the masseter, temporalis and zygomaticomandibularis of Suncus murinus which has no zygomatic arch. Detailed dissection of eight head halves of four S. murinus was performed. In S. murinus, small muscle bundle was observed to be adjoined with the lateral surface of the temporalis. This muscle bundle was completely separated from the masseter. Based on the positional relationships between the muscle bundle and supplying nerves, we conducted that the bundle corresponded to the zygomaticomandibularis of human described in our previous study (Shimokawa et al., 1999). In addition, some differences in the nerve distribution to the masticatory muscles were observed in S. murinus as compared with humans with respect to the following points: 1) The additional supplying branch to the masseter originated from the auriculo-temporal nerve: 2) The common trunk of the masseteric nerve and the nerve to the posterior part of the temporalis penetrated the superior head of the lateral pterygoid. A possible model to account for these differences based on the positional relationships among the muscles and supplying nerves is presented.
在本研究中，我们调查了没有颧弓的臭鼩的咬肌、颞肌和颧下颌肌的结构及神经支配。对4只臭鼩的8个半侧头部进行了详细解剖。在臭鼩中，观察到小肌束与颞肌的外侧面相连。该肌束与咬肌完全分离。根据肌束与供应神经之间的位置关系，我们推断该肌束相当于我们之前研究（Shimokawa等人，1999年）中描述的人类的颧下颌肌。此外，与人类相比，在臭鼩中观察到咀嚼肌神经分布在以下方面存在一些差异：1）咬肌的额外供应分支起源于耳颞神经；2）咬肌神经和颞肌后部神经的共同主干穿过翼外肌上头。基于肌肉与供应神经之间的位置关系，提出了一个解释这些差异的可能模型。
