Located on the ventral portion of the medulla, these paired white matter structures contain motor fibers of the corticospinal and corticobulbar (together known as the pyramidal) tracts on their anterior surface. The lower border of the medullary pyramids is marked by the decussation of the pyramids where the two tracts cross. Medially, they are bordered by the anterior median fissure and laterally by the anterolateral sulcus where the hypoglossal nerve is located. The olive is also located beside each pyramid. The posterior column is located behind the pyramids on the medulla.