Spinotectal tract
Tractus spinotectalis
An ascending pathway in the anterolateral spinal cord that carries pain and touch signals to the superior colliculus of the midbrain.
At a glance
- English
- Spinotectal tract
- Latin (TA2)
- Tractus spinotectalis
- System
- Nerve
- Region
- Whole body
- Side
- Single, on the midline
About the spinotectal tract
The spinotectal tract, also called the spinomesencephalic tract or the spino-quadrigeminal system of Mott, is one of the ascending pathways of the anterolateral system. It carries information from the body to the tectum, the roof of the midbrain, rather than to the thalamus. In the spinal cord it is not a sharply separate bundle. It runs in the anterolateral white matter, just in front of the lateral spinothalamic tract, and its fibres are largely mixed with spinothalamic ones; for this reason it is often treated as a branch of the spinothalamic system.
Its cells of origin lie in the posterior horn, in the same zones that give rise to the spinothalamic fibres. Their axons cross to the opposite side in the anterior white commissure and then climb in the anterolateral funiculus. In the medulla the fibres pass lateral to the inferior olivary nucleus; in the pons they lie ventrolateral to the superior olivary nucleus and then shift towards the trigeminal spinal tract. In the upper pons and midbrain they settle within the inner part of the lateral lemniscus, and finally they end in the deep layers of the superior colliculus, with some reaching the inferior colliculus and the periaqueductal grey matter.
The superior colliculus builds a map of the space around the body from visual, auditory and body signals. Input from the spinotectal tract lets a sudden touch or painful stimulus on the skin turn the eyes and head towards its source. Fibres ending in the periaqueductal grey take part in the brain's own control of pain.
Since its fibres travel with the spinothalamic tract, the pathway is cut along with it in an anterolateral cordotomy and in injuries that damage the front and side of the cord.
Course and supply
- Supplies
- Carries pain, temperature and touch signals from the opposite side of the body to the superior colliculus, helping to turn the eyes and head towards a stimulus.
- Blood supply
- Runs in the anterolateral funiculus, supplied by the anterior spinal artery.
Anthromica
See the spinotectal tract where it really sits, with every layer of the body around it.
- Every layer, one body. Peel from muscle to bone, nerve, vessel and organ, and turn it any way.
- English and Latin. Every structure named the way your exam names it.
- Quiz until it sticks. Short drills on the structures you keep missing.
Free to start. No card.
