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a brief treatise on a subject of interest; published in the form of a booklet (同)pamphlet
an extended area of land (同)piece of land, piece of ground, parcel of land, parcel
a system of body parts that together serve some particular purpose

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広大な土地(地域),(土地・海・空などの)広がり《+of+名》 / (器官の)管,(神経の)索
(おもに宗教・政治などの宣伝用の)小冊子,パンフレット

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2017/12/27 23:12:07」(JST)

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The spinothalamic tract (also known as anterolateral system or the ventrolateral system) is a sensory pathway from the skin to the thalamus. From the ventral posterolateral nucleus in the thalamus, sensory information is relayed upward to the somatosensory cortex of the postcentral gyrus.

The spinothalamic tract consists of two adjacent pathways: anterior and lateral. The anterior spinothalamic tract carries information about crude touch. The lateral spinothalamic tract conveys pain and temperature.

In the spinal cord, the spinothalamic tract has somatotopic organization. This is the segmental organization of its cervical, thoracic, lumbar, and sacral components, which is arranged from most medial to most lateral respectively.

The pathway decussates at the level of the spinal cord, rather than in the brainstem like the posterior column-medial lemniscus pathway and lateral corticospinal tract.

Structure

There are two main parts of the spinothalamic tract (STT):

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 dorsal column-medial lemniscus tract, uses three neurons to convey sensory information from the periphery to conscious level at the cerebral cortex.

Pseudounipolar neurons in the dorsal root ganglion have axons that lead from the skin into the dorsal spinal cord where they ascend or descend one or two vertebral levels via Lissauer's tract and then synapse with secondary neurons in either the substantia gelatinosa of Rolando or the nucleus proprius. These secondary neurons are called tract cells.

The axons of the tract cells cross over (decussate) to the other side of the spinal cord via the anterior white commissure, and to the anterolateral corner of the spinal cord (hence the spinothalamic tract being part of the anterolateral system). Decussation usually occurs 1-2 spinal nerve segments above the point of entry. The axons travel up the length of the spinal cord into the brainstem, specifically the rostral ventromedial medulla.

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.

Function

The types of sensory information transmitted via the spinothalamic tract are described as affective sensation. This 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, aka ARAS)
- Spino-Mesencephalic-Limbic (for affective impact of pain).

Anterolateral system

In the nervous system, the anterolateral system is an ascending pathway that conveys pain,^[1] temperature (protopathic sensation), and crude touch from the periphery to the brain. It comprises three main pathways:

Name	Destination	Function
spinothalamic tract (lateral and 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 posterior column-medial lemniscus pathway, the axons of second-order neurons in the spinothalamic tracts cross at every segmental level in the spinal cord. This fact aids in determining whether a lesion is in the brain or the spinal cord. With lesions in the brain stem or higher, deficits of pain perception, touch sensation, and proprioception are all contralateral to the lesion. With spinal cord lesions, however, the deficit in pain perception is contralateral to the lesion, whereas the other deficits are ipsilateral. See Brown-Séquard syndrome.

Unilateral lesions usually cause contralateral anaesthesia (loss of pain and temperature). Anaesthesia will normally begin 1-2 segments below the level of lesion, due to the sensory fibers being carried by dorsal-lateral tract of Lissauer up several levels upon entry into the spinal cord, and will affect all caudal body areas. This is clinically tested by using pin pricks.

References

^ "Chapter 25:Neural Mechanisms of Cardiac Pain: The Anterolateral System". Retrieved 2009-11-26.

UpToDate Contents

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English Journal

[Pain perception and peripheral pain localization in angina pectoris].

Droste C1.
Zeitschrift fur Kardiologie.Z Kardiol.1988;77 Suppl 5:15-33.
PMID 3066037

「脊髄視床路」

Spinothalamic tract
	Spinothalamic tracts are grouped, in blue at bottom right.
	Diagram of the principal fasciculi of the spinal cord. (Anterior and posterior spinothalamic fasciculus is labeled at bottom left.)
Details
Identifiers
Latin	Tractus spinothalamicus
NeuroNames	ancil-114
TA	A14.1.04.138
FMA	72644
	Anatomical terms of neuroanatomy [edit on Wikidata]

　　[★]

英: spinothalamic tract
ラ: tractus spinothalamicus
関: 上行性伝導路

図：BET.332

概念

体幹や四肢の皮膚感覚の中でも生命の維持に重要な原始的感覚、すなわち痛覚、温度覚、および識別力のない触覚や圧覚を中枢に伝達する原始性感覚路をいう。系統発生学的に古い伝導路である。

走行

後根から入力を受けた後、直ちに交差して対側の前側索を上行し、視床に達する。
脊髄視床路起始ニューロンには、腹側基底核や後核群など視床外側部に終わるものと、髄板内核など内側部に終わるものがある(SP.231)。
温覚　＋　痛覚　＋　粗大な触圧覚(識別力なし)(B.P-2)

感覚の伝導路

「tract」

　　[★]

n.

路

関: tractus

[urlChapter_25:Neural_Mechanisms_of_Cardiac_Pain:_The_Anterolateral_System-1] "Chapter 25:Neural Mechanisms of Cardiac Pain: The Anterolateral System". Retrieved 2009-11-26.

v t e Sensory receptors
Touch	Mechanoreceptor Vibration Lamellar corpuscle Light touch Tactile corpuscle Pressure Merkel nerve ending Stretch Bulbous corpuscle
Pain	Free nerve ending Nociceptors
Temperature	Thermoreceptors
Proprioception	Golgi organ Muscle spindle Intrafusal muscle fiber Nuclear chain fiber Nuclear bag fiber
Other	Hair cells Baroreceptor

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案内

案内

tractus spinothalamicus