- Located in the posterior funiculi.
- Ascend the cord ipsilaterally until the medulla oblongata, where they decussate, at the cervico-medullary junction.
- In the spinal cord, at the level of T-6, the columns divide and form two bundles or fascicles of axons: the gracile fascicle and the cuneate fascicle.
- The gracile fascicle ascends medially, and contains fibers from the ipsilateral sacral, lumbar, and lower thoracic segments. The cuneate fascicle ascends laterally and contains fibers from the upper thoracic and cervical segments.
After the fibers decussate
at the cervico-medullary junction
, they continue travelling by way of the medial lemniscus
to the VPL
(Ventral Posterior Lateral
) nucleus of the thalamus
. The sensory
information they carried to the thalamus
then goes from the thalamus to the post central gyrus
of the parietal lobe
, to the somatic sensory cortex
(AKA somesthetic cortex
) for localization.
Relay the following modalities: discriminative touch
, and joint position
sense. Testing in the office is done by testing joint position
sense, swaying (Romberg's Test