Between the spinal cord and the obex, the roof plate of the neurotube is closed over by neural pathways and neuronal cell groups. The dorsal column pathways fasciculus gracilis and fasciulus cuneatus target the respective gracilis and cuneatus nuclei. A central canal remains in the center of the neurotube gray mater. The hypoglossal nuclear column extend from the open medulla caudally into the closed medulla. The nerve rootlets emerge ventrally from between the pyramid and the inferior olive.