Diagram showing a few of the connections of afferent (sensory) fibers of the posterior root with the efferent fibers from the ventral column and with the various long ascending fasciculi. (Spinotectal fasciculus labeled at bottom right.)
Diagram of the principal fasciculi of the spinal cord. (Spinotectal fasciculus labeled at bottom left.)
The spinotectal tract and/or spinomesencephalic tract (also spinotectal fibers, spinomesencephalic fibers,[1]spinotectal fasciculus, or spino-quadrigeminal system of Mott[2]) is one of the ascending tracts in the anterolateral system of the spinal cord that is involved in processing of pain and visceral sensations.[3] The tract is involved in the processing of pain sensation, and reflex turning of the head and trunk in the direction of painful stimuli.[1] It projects contralaterally to the midbrain tectum.
Sources may distinguish between a distinct spinotectal tract which projects to the visual reflex system, and spinomesencephalic tract which projects to structures involved in pain processing.[1]
The ST/SM tract arises mostly in the laminae I and V (but, to a lesser extent, also laminae IV and VI-VIII) of the spinal cord.[4] It arises in same region of the spinal cord grey matter as the spinothalamic tracts.[3]
It mostly crosses over (decussates) to ascend contralaterally, but uncrossed ipsilaterally ascending fibers are prominent in the upper cervical levels.[4]
^ abcdefghPatestas, Maria A.; Gartner, Leslie P. (2016). A Textbook of Neuroanatomy (2nd ed.). Hoboken, New Jersey: Wiley-Blackwell. pp. 112, 203–204, 224–225. ISBN978-1-118-67746-9.
^ abcKiernan, John A.; Rajakumar, Nagalingam (2013). Barr's The Human Nervous System: An Anatomical Viewpoint (10th ed.). Philadelphia: Wolters Kluwer Lippincott Williams & Wilkins. p. 74. ISBN978-1-4511-7327-7.
