刺猬的皮肌及其神经支配

刺猬的皮肤,包括皮肤肌和皮下脂肪,是一个质量很大的器官,平均占体重43形,最多可达57％以上。刺猬的皮肌,如果不是动物界中最发达的,也是非常发达的,尤其环状皮肌带约占体重11％(赵以炳等1958)。在功能上,刺猬的皮肌是重要的生理性体温调节器官,背面带针刺的部分有保温御寒作用,腹部有散热机能(赵以炳等1950a)。清醒的刺猬当遇到强敌或其它干扰时,常蜷缩成带剌的球。不活动的冬眠刺猬也取同样姿势,以防侵害。可以说,蜷缩是一种主动的保护性行为,这种强烈的蜷缩主要是由于环状皮肌带持续有力的收缩。尤其令人惊奇的是冬眠时的蜷缩,这是在一般生理活动明显降低的

THE CUTANEOUS MUSCLES OF HEDGEHOG AND THEIR INNERVATION

The rolled-up posture of the hibernating hedgehog is maintianed by the tonic contraction of the powerful orbicularis muscles. Experimental investigation of the rolling activity will help to elucidate the nervous mechanism of hibernation. The present work is concerned with a general anatomic survey of the three groups of integumental museles and their motor innervation, and a detailed study of the structure and function of the most well-developed orbicularis muscle band.The cutaneous muscles of hedgehog are innervated by the ventral thoracic nerve (VTN), a branch of the brachial plexus. The areas of innervation by the nine branches of VTN appear in stripes, arranged in sequential order from rostral to caudal and from dorsal to ventral regions with some overlapping.By treating each branch of VTN, one at a time, in horseradish peroxidase(HRP) solution and treating the frozen sections of the cervicothoracic segments of spinal cord histoehemically, the motoneurones supplying the cutaneous muscles are found in the lateral parts of the ventral horn between C5 and T2, more or less concentrated in the segments of C7, C8, and T1. The orderly rostro-caudal arrangement of the innervation areas of the nerve branches is generally reflected in the location of their motoneu-rone columns in the spinal cord.The powerful orbicularis muscle band in hedgehog and the panaiculus carnosus in cat and rabbit are homologous organs. The cutaneous muscles in mammals are striated muscles of dermatomic origin. Anatomic localization of the dermo-motoneurones in the spinal cord of hedgehog provides new information on the composition of motoneurone column in the ventral horn.