Nonparenchymatous organ Neural tree organ FMA:61284 Neural tree organNonparenchymatous organ which has as its parts an aggregate of neurons (nuclei or ganglia) and their axons which are grouped into fasciculi by connective tissue to form elongated, cable-like structures that are arranged into a tree. Examples: vagus nerve, cervical spinal nerve, T2 spinal nerve (including the nuclei and ganglia of these nerves). fma