A Histological Examination of the Lumbar Sympathetic Trunk

Abstract

Current gross anatomical and histological descriptions of the lumbar sympathetic trunk suggest that its neuronal cell bodies are located in discrete ganglia that are linked to each other by nerve fibres. Despite well‐documented variations in the macroscopic morphology of the lumbar sympathetic trunk (e.g., number and placement of ganglia), a detailed histological examination of the arrangement of the neuronal cell bodies within the trunk is lacking. Thus, the present study aims to examine the microscopic organization of the lumbar sympathetic trunk using standard histological techniques. In our preliminary investigation, a 10 cm length of the lumbar sympathetic trunk (including ganglia and interganglionic fibres) was serially‐sectioned (5 μm thick) in the longitudinal plane and then stained with Haematoxylin & Eosin to visualize the location of neuronal cell bodies throughout the 10 cm length. This examination revealed that the neuronal cell bodies are not confined to specific “ganglionic” swellings; a finding which is inconsistent with the current textbook descriptions of the lumbar sympathetic trunk. The presence of neuronal cell bodies throughout the “interganglionic” regions of the lumbar sympathetic trunk may have implications for future investigations of sympathetic activity in this region, specifically related to understanding functional deficits associated with this nerve tissue.