[TA] fibers that arise in the cuneate and gracile nuclei, pass in a curving course across the midline of the medulla oblongata, and form the contralateral medial lemniscus; may also designate other fibers such as those of the olivocerebellar tract that arch through the substance of the medulla and may traverse the sensory decussation. SYN: fibrae arcuatae internae [TA].
