The crossed part of the pyramid path; threads to the external motor neuron group.

Tractus cortico-spinalis lateralis; filaments to cellulae motoriae laterales.

Throughout its progression down through the dorsal lateral cord , the tractus cortico-spinalis lateralis emits filaments into the various nuclei of the outer motor neuron group . This is particularly evident in the swelling of the neck and lumbar. Here are neatly and neatly, in good somatotop order, the motor neuron nuclei for the upper and lower extremities, respectively.