cuneate

Cuneate is an adjective meaning wedge-shaped, derived from the Latin cuneus. In anatomy, the term is used most often to describe structures in the dorsal column–medial lemniscus pathway and in other wedge-shaped regions of the brain.

In the spinal cord, the dorsal columns are subdivided into the gracile and cuneate fasciculi. The fasciculus cuneatus contains ascending fibers that carry fine touch, vibration, and conscious proprioception from the upper trunk and upper limbs above roughly the level of T6. These fibers terminate in the nucleus cuneatus in the dorsal medulla, where they synapse onto second-order neurons. The second-order neurons then cross (as internal arcuate fibers) and ascend as the medial lemniscus to the thalamus, eventually reaching the somatosensory cortex.

The nucleus cuneatus is a prominent dorsal medullary nucleus adjacent to the gracile nucleus. It forms part of the dorsal column nuclei and is specifically the relay for sensory information from the upper body. The cuneate tubercle is the swelling on the dorsal surface of the medulla produced by the underlying nucleus cuneatus.

Cuneus is a related term referring to a wedge-shaped area of the occipital lobe, part of the visual cortex, bounded by the calcarine sulcus. While the root idea is wedge-shaped, the term cuneus is the preferred anatomical name for this region rather than cuneate, which is more commonly used for dorsal column structures.

Clinical relevance includes deficits in fine touch and proprioception of the upper limb with damage to the cuneate pathway or the nucleus cuneatus, underscoring their role in somatosensory perception.