Spinal Ascending Tracts

Question 1

Gracilis (Slender)

Answer 1

Medial portion of dorsal funiculius

All cord levels (only carries T6 below info)

Ipsilateral

Bypass gray matter, synapse in nucleus gracilis in M.O. 3 neuron pathway

Vibratory and Kinesthetic Sensation, Two point touch discrim.

Rombergs test for lesion, lose function on SAME SIDE as lesion

Question 2

Cuneatus (Wedge Shape)

Answer 2

Lateral aspect of Dorsal Funiculus

T5 or T6 and above

Ipsilateral

Bypass gray matter, synapse in nucleus cuneatus of M.O. 3 neuron pathway

Vibratory, Kinesthetic sensations and two touch discrim.

Romberg’s test, loss of function on SAME SIDE as lesion

Question 3

Anterior Spinothalamic

Answer 3

Anterior Funiculus

All cord levels

Contralateral, cross gradually

Synapse in VPL nucleus of thalamus, 2 order neuron

Light touch

Loss of light touch on OPPOSITE side of lesion

Question 4

Lateral Spinothalamic

Answer 4

Lateral Funiculus

All cord levels

Contralateral, crosses abruptly

Synapse in VPL nucleus of Thalamus, 2 order neuron

Pain and thermal input

Pain and temperature loss on OPPOSITE side of lesion

Question 4

Posterior Spinocerebellar (best friends with gracilis)

Answer 4

Along periphery of Lateral Funiculus, posterior to the Anterior Spinocerebellar tract

Most fibers do not cross. ipsilateral

Originates from cell bodies in nucleus dorsallis. Tract not found below L3. Terminates in cerebellum via inferior cerebellar peduncle.

Proprioceptive input for mainly fine movements. What has JUST happened with the muacle

Loss of proprioception for fine movements on same side of lesion

Question 5

Anterior Spinocerebellar

Answer 5

Along periphery of Lateral Funiculus, anterior to Posterior Spinocerebellar tract

2 crossovers once cord in cerebellum

Most originate from lumbosacral gray lamina, terminate in cerebellum via Superior Cerebellar Peduncle, 2 neuron pathway

Sends gross lower body movement input to cerebellum, also sends input of what ABOUT to happen from motor neurons there

Depends on lesion location and side of tract

Question 6

Cuneocerebellar

Answer 6

From pectoral girdle and upper extremity

Ipsilateral

Enter cervical cord and ascend, synapse in M.O. Accessory Cunate Nucleus, then ascend to cerebellum via inferior cerebellar peduncle

Sends FINE proprioceptive movment of Upper Extremity input to cerebellum. Also sends input of what is about to happen from motor neurons there.