At the level of the closed medulla in the posterior white column, two large nuclei namely the gracile nucleus and the cuneate nucleus can be found. The two nuclei receive the impulse from the two ascending tracts: fasciculus gracilis and fasciculus cuneatus.
In the posterior white column of the medulla oblongata, two significant nuclei are located: the slender nucleus and the cone-shaped nucleus. These nuclei receive signals from the two ascending pathways: the gracile tract and the cuneate tract.