Spinal Tracts

Question 1

Dorsal columns/Medial Lemniscal (DCML)

Answer 1

Ascending; sensations of proprioception, vibration, and tactile discrimination.

Fibers ascend to medulla, decussate to for ML, thalamus, somatosensory cortex

Question 2

Fasciculus cuneatus

Answer 2

UE tract for DCML

Laterally located

Question 3

Fasciculus gracilis

Answer 3

LE tracts for DCML

Medically located

Question 4

Spinothalamic tracts

Answer 4

Ascending; Pain and temperature (lateral) and crude touch (anterior)

Tract ascends 1-2 segments up ipsilateral side THEN crosses and synapses and ascends in ALS/VLS

Question 5

Spinocerebellar tracts

Answer 5

Ascending; Proprioception info from muscle spindles, GTOs, and touch and pressure receptors TO cerebellum for voluntary mvmt control

Dorsal—> ipsi inferior cerebellar peduncle
Ventral—> contra and ipsi superior cerebellar peduncle

Question 6

Spinorecticular tracts

Answer 6

Deep and chronic to reticular formation

Question 7

Corticospinal tracts

Answer 7

Descending; voluntary motor control

primary motor cortex, cross in medulla, (pyramidal decussation) to lateral tract

10% don’t cross and descend in anterior tract

Question 8

Vestibulospinal tracts

Answer 8

Descending; Facilitates quick mvmt in reaction to sudden changes, important for control of muscle tone, antigravity, and postural reflexes

Lateral: crossed
Medial: crossed and uncrossed (only cervical)

Question 9

Rubrosponal tracts

Answer 9

Descending; assist in motor function

Contra red nucleus to lateral white columns to spinal grey

Question 10

Reticulospinal system

Answer 10

Descending; dorsal gray-modifies transmission of pain; ventral gray-influences gamma motor neurons and spinal reflexes

Reticular formation to ventral and lateral columns to terminate in gray

Question 11

Tectospinal

Answer 11

Descending; assists in head turning response to sudden visual or auditory stimuli

Superior colliculus and descends to ventral gray