[OT 104] Lec. 4: White Matter - Ascending Sensory Tracts & Pathways

First order

• dorsal root ganglion

Second order

• decussates and ascends to higher level of brain

Third order

• thalamus

Dorsal Column Medial Lemniscus (DCML)

Function: fine touch, proprioception, two-point discrimination

Location: dorsal column

Origin: posterior root ganglion (skin, joints, tendons)

Decussation: medial lemniscus

Ending: thalamus

Anterior Spinothalamic Tract (AST)

Function: crudely localized touch - aware but cant localize

Lateral Spinothalamic Tract (LST)

Function: discriminative, can be localized, sharp pain and temparature (a-delta and c-fibers)

Location: ventrolateral column

Origin: skin

Decussation: spinal cord close to level of entry

Ends: thalamus

Dorsal Spinocerebellar Tract (DSCT)

Function: receives ms joints information and is responsible for movement and position mechanisms. dorsal: coordinates limb and posture

Location: lateral column

Origin: ms spindle, GTO, touch and pressure receptors

Ends: I/L inferior cerebellar peduncle

Anterior Spinocerebellar Tract (ACST)

Function: receives ms joints information and is responsible for movement and position mechanisms. anterior: provides information from skin, controlled movement

Location: lateral column

Origin: ms spindle, GTO, touch, and pressure receptors

Ends: C/L and I/L superior cerebellar peduncle

Spinoreticular tract (SRT)

Function: deep, chronic pain, consciousness

Location: ventrolateral column (polysynaptic, diffuse pathway)

Origin: deep somatic structures

Ends: brainstem, reticular formation