Trapezoid body

The trapezoid body is part of the acoustic pathway. It is a bundle of fibers and cells in the pontine tegmentum. It consists of fibers arising from the ventral cochlear nucleus. A collection of nerve cells inside forms a trapezoid nucleus. The superior olivary nucleus is situated on the dorsal surface of the trapezoid body. Most nerve fibers pass directly from the olivary nuclei to the inferior colliculus.

Axons leaving the ventral cochlear nucleus (VCN) form a broad pathway that crosses under the brain stem in the trapezoid body. A thin pathway, the intermediate acoustic stria, also leaves the VCN, merging with the trapezoid body close to the superior olivary complex, where many of its axons synapse. Axons leaving the dorsal cochlear nucleus (DCN) form the dorsal acoustic stria, which reaches primarily the contralateral dorsal nucleus of the lateral lemniscus and the central nucleus of the inferior colliculus.