Spinothalamic tract
Spinothalamic tract | ||
---|---|---|
Decussation Anterior white commissure | | |
Parts | Anterior and lateral tracts | |
From | Skin | |
To | Thalamus | |
Artery | Anterior spinal artery | |
Function | Gross touch and temperature | |
Identifiers | ||
Latin | tractus spinothalamicus | |
MeSH | D013133 | |
NeuroNames | 2058, 810 | |
TA98 | A14.1.04.138 | |
TA2 | 6102 | |
FMA | 72644 | |
Anatomical terms of neuroanatomy] |
The spinothalamic tract is a part of the anterolateral system or the ventrolateral system, a sensory pathway to the
The spinothalamic tract consists of two adjacent pathways: anterior and lateral. The anterior spinothalamic tract carries information about
In the
components, which is arranged from most medial to most lateral respectively.The pathway crosses over (
Structure
There are two main parts of the spinothalamic tract:
- The lateral spinothalamic tract transmits pain and temperature.
- The anterior spinothalamic tract(or ventral spinothalamic tract) transmits crude touch and firm pressure.
The spinothalamic tract, like the
The axons of the tract cells cross over (decussate) to the other side of the spinal cord via the
Traveling up the brainstem, the tract moves dorsally. The neurons ultimately synapse with third-order neurons in several nuclei of the thalamus—including the medial dorsal, ventral posterior lateral, and ventral posterior medial nuclei. From there, signals go to the cingulate cortex, the primary somatosensory cortex, and insular cortex respectively.
Anterior spinothalamic tract
The anterior spinothalamic tract (Latin: tractus spinothalamicus anterior) or ventral spinothalamic fasciculus situated in the marginal part of the
This is a somewhat doubtful fasciculus and its fibers are supposed to end in the thalamus and to conduct certain of the touch impulses. More specifically, its fibers convey crude touch information to the VPL (ventral posterolateral nucleus) part of the thalamus.
The fibers of the anterior spinothalamic tract conduct information about pressure and crude touch (protopathic). The fine touch (epicritic) is conducted by fibers of the medial lemniscus. The medial lemniscus is formed by the axons of the neurons of the gracilis and cuneatus nuclei of the medulla oblongata which receive information about light touch, vibration and conscient proprioception from the gracilis and cuneatus fasciculus of the spinal cord. This fasciculus receive the axons of the first order neuron which is located in the dorsal root ganglion that receives afferent fibers from receptors in the skin, muscles and joints.
Lateral spinothalamic tract
The lateral spinothalamic tract (or lateral spinothalamic fasciculus), is a bundle of
Together with the anterior spinothalamic tract, the lateral spinothalamic tract is sometimes termed the secondary sensory fasciculus or spinal lemniscus.
Anatomy
The neurons of the lateral spinothalamic tract originate in the
Function
The types of sensory information means that the sensation is accompanied by a compulsion to act. For instance, an itch is accompanied by a need to scratch, and a painful stimulus makes us want to withdraw from the pain.[citation needed]
There are two sub-systems identified:
- Direct (for direct conscious appreciation of pain)
- Indirect (for affective and arousal impact of pain). Indirect projections include
- Spino-Reticulo-Thalamo-Cortical (part of the ascending reticular arousal system, also known as ARAS)
- Spino-Mesencephalic-Limbic (for affective impact of pain).
- Spino-Reticulo-Thalamo-Cortical (part of the
Anterolateral system
In the
Name | Destination | Function |
spinothalamic tract ( anterior ) |
thalamus | important in the localization of painful or thermal stimuli |
spinoreticular tract | reticular formation | causes alertness and arousal in response to painful stimuli |
spinotectal tract | tectum |
orients the eyes and head towards the stimuli |
Clinical significance
In contrast to the axons of second-order neurons in
Unilateral lesions usually cause contralateral
See also
- Rostral ventromedial medulla
- Periaqueductal gray
- Neothalamus
References
This article incorporates text in the public domain from page 760 of the 20th edition of Gray's Anatomy (1918)
- ^ "Chapter 25:Neural Mechanisms of Cardiac Pain: The Anterolateral System". Archived from the original on 2010-08-11. Retrieved 2009-11-26.