Spinal Tracts/pathways

Front 1

Fasciculus cutaneus

Back 1

Ascending Sensory Pathway
*Starts skin receptors of UE and neck
*Enters spinal cord through dorsal root ganglion
*Axons from upper limb occupy lateral section of dorsal column
*Travel to medulla
*Cross midline and ascend to Thalamus (sensory switching station)
*Then travel from Thalamus to sensory cortex
(Carries discriminative touch, ie proprioception, vibration, 2 point discrimination, and graphesthesia from neck, trunk, and UE's

Front 2

Fasciculous gracilis

Back 2

Ascending Sensory Pathway
*Starts in skin receptors of LE and trunk
*Enters spinal cord through dorsal root ganglion
*Axons from lower limb occupy medial section of dorsal column
*Travel to medulla
*Cross midline to ascend to Thalamus (sensory switching station)
*Then travels from thalamus to sensory cortex
(Carries discriminative touch, ie proprioception, vibration, 2 point discrimination, and graphesthesia from trunk and LE's)

Front 3

Spinothalamic Tract

Back 3

Ascending Sensory Pathway
*Carries information from periphery, ie skin receptors
*Carries to dorsal root ganglia of spinal cord
*Travels to Thalamus
(Sensory tract for PAIN. Also, light touch and temperature.)

Front 4

Anterior Spinocerebellar

Back 4

Ascending Sensory Pathway
*Starts at thoracic spinal cord in anterior horn
*Cross to opposite side
*Ascend to contralateral anterior spinocerebellar tract of midbrain
*Then enter cerebellum
*Most fibers recross so that cerebellum gets information from both sides of lower body.
(This information does not reach conscious awareness and contributes to automatic movements and postural adjustements. Subconscious proprioception.)

Front 5

Posterior Spinocerebellar

Back 5

Ascending Sensory Pathway
*Starts in dorsal column and ascends
*Travels through medulla
*Remains ipsilateral
*Travels to cerebellum
(Sensory Tract for ipsilateral subconscious proprioception)

Front 6

Medial Corticospinal

Back 6

Descending Motor Pathway: cortex to spinal cord
*Starts at cerebral cortex
*Travels down spinal cord
*Does NOT cross ie ipsilateral
*Travels down through internal capsule to brain stem
*Ends in thoracic cord (anterior horn cell)
(involved w/ voluntary control of posture and proximal movements ie neck shoulder and trunk movements)

Front 7

Lateral Corticospinal

Back 7

Descending Motor Pathway: cortex to spinal cord
*Starts at cerebral cortex
*Pass down through internal capsule
*Travels through midbrain, pons, pyramids of medulla
*Crosses to other side ie contralateral
*Ends in anterior horn
(Involved in contralateral voluntary fine movements.)

Front 8

Rubrospinal

Back 8

Descending Motor Pathway
*Responsible for innervating upper limb flexors
*Also lateral reticulospinal facilitates flexor muscles and inhibits extensors
*Starts in red nucleus of midbrain
*Crosses to opposite side
*Descends through pons to spinal cord
*Innervates muscles listed above

Front 9

Tectospinal

Back 9

Descending Motor Pathway
*Starts in midbrain
*Crosses in Pyramids
*Ends in lower motor neurons that project to spinal cord
*Ends in cervical spine (Acts to reflexively turn head toward sound)

Front 10

Vestibulospinal

Back 10

Descending Motor Pathway
*Starts in vestibular nuclei of medulla
*Travels to ipsilateral lower motor neurons that innervate postural muscles and limb extensors
*Receives information about head position and movement