tectospinal

The tectospinal tract, or tectospinal pathway, is a descending motor pathway of the central nervous system. It originates primarily from neurons in the superior colliculus of the midbrain (the tectum) and descends to the upper cervical segments of the spinal cord. The tract fibers cross to the contralateral side in the midbrain tegmentum and descend through the brainstem to terminate mainly on interneurons and, to a lesser extent, on alpha motor neurons in the cervical spinal cord (C1–C5). Some sources note termination on interneurons that influence neck and upper trunk muscles.

Functionally, the tract mediates reflexive head and neck movements in response to visual, auditory, or somatosensory stimuli, helping to orient the head toward a stimulus. It works in concert with other brainstem pathways and higher motor pathways to coordinate orienting responses.

Clinical significance is limited by its relatively small size in humans compared with other motor tracts. Lesions affecting the tectospinal pathway can impair reflex head-turning toward stimuli and disrupt orienting responses, though many functions are preserved by other motor systems such as the corticospinal and reticulospinal tracts.