Classification of the abdominal splanchnic nerves--a preliminary attempt to re-evaluate their nomenclatures.

The abdominal splanchnic nerves were observed in 22 cadavers (41 sides). The purpose of the study is to give more accurate definition to each nerve, for there are uncertainties in the nomenclature of these nerves. According to PNA, the abdominal splanchnic nerves are classified into three categories, on the basis of their sizes and their levels, namely Nn. splanchnici major, minor, and imus. Although Mitchell (1935) had already claimed that more attention should be given to the levels of ganglia which gave rise to these nerves, no revision has ever been made. Moreover, there still remains the matter of their destinations, which are more significant in defining them. Therefore, in addition to the conventional criteria for the classification, destinations of the nerves were taken into consideration. In the present study, 36 out of 41 sides were grouped into four types according to the said criteria. 5 exceptional cases were interpreted as results of minor modifications of these four types. Naturally, what is important in describing these nerves is to give clear idea about the actual condition of them. It is expected to give more reasonable nomenclature to these nerves based on the present result.