小儿颈神经襻的形成及其分支

A STUDY OF THE FORMATION AND BRANCHES OF THE ANSA CERVICALIS OF CHILDREN

前言关于颈神经襻的研究,就所涉猎到的文献言时,对于襻的形成、位置及分支等虽均有所记述,但多不甚详尽。在襻的形成方面:Gray[1]、Morris[2]、平泽兴[3]、Cunningham[4]及Grant[5]等在其所著的解剖学教本中,指出由第2、3颈神经发支连结成为下行颈神经(nervus descendens cervicalis)与舌下神经降支会合成襻.

The formation,position,and branches of ansa cervicalis of 100 children were in-vestigated.Ansa cervicalis was found in 96 cases,among them 62 have one ansa,33have two ansae and one has three ansae.Ansa cervicalis is classified into four types according to the different sources of thenervus descendens cervicalis of which it is composed.The majority of them are of thesecond type(74 cases);the third type are listed next in order(18 cases),the first andfourth types are rarely seen.In our series,in addition to the 2nd,3rd and 4th cervical nerves,the 1st and 5thnerves also enter the formation of the ansa.With regard to the position of the ansae,it was found that 60.4%of them aresituated behind the internal carotid vein and 54.2%of them descend below the levelof the cricoid cartilage.The ansae,as related to the carotid sheath,are located within the sheath in 88cases(91.7%),and outside of the sheath in 8 cases(8.3%).According to our investigation,with the exception of the nerve of m.thyreohyoideuswhich arise from the hypoglossal nerves,the infrahyoid muscles(including m.omohyoi-deus,sternothyroideus,and sternohyoideus)are supplied by the descending branches ofthe hypoglossal nerve in 184 cases(30.7%)and by ansa cervicalis in 277 cases(46.2%).