Tracts and Nuclei

Question 1

Fasciculus Gracilis

Answer 1

1) Carries primary afferents with proprioception, vibration, and fine touch from the lower limb
2) Cell bodies are in dorsal root ganglia
3) Destined for the nucleus fasiculus in the caudal medulla
4) don’t decussate

lesions would cause loss of proprioception, vibration, and fine touch to the ipsilateral lower limb

Question 2

Nucleus Gracilis

Answer 2

1) proprioception, vibratory sensation, fine touch from the ipsilateral lower limb
2) recieve input from primary afferents
3) send axons into the medial lemniscus to the VPL
4) final destination is the postcentral gyrus
5) fibers will decussate
gone by middle medulla (open)

Question 3

Fasciculus Cuneatus

Answer 3

1) Carries primary afferents from the ipsilateral upper limber of proprioception, vibration, and fine touch
2) Cell bodies in the dorsal root ganglia
3) Destined for the nucleus cuneatus in the caudal medulla
4) don’t decussate

lesions would cause loss of proprioception, fine touch, and vibratory sense to the ipsilateral upper limb

Question 4

Nucleus cuneatus

Answer 4

1) Proprioception, fine touch, vibration from the ipsilateral upper limb
2) input from primary afferents of the upper limb carried by fasciculus cuneatus
3) sends axons into the medial lemniscus to the VPL
4) final destination is the post central gyrus
5) fibers will decussate
gone by middle medulla

Question 5

Spinal trigeminal tract

Answer 5

1) Carries descending primary afferents from the ipsilateral face with pain, temp, crude touch
2) cell bodies are in the trigeminal ganglion
3) bound for the spinal nucleus of V
4) do not decussate

Question 6

spinal nucleus of V (spinal trigeminal nucleus)

Answer 6

1) pain, temp, crude touch from ipsilateral face
2) input from from primary afferents traveling in the spinal tract of V
3) sends axons to thru the VTT to the VPM
4) Bound for the lateral portion of postcentral gyrus
5) do decussate

Question 7

Anterolateral system

Answer 7

1) Pain, temp, crude touch pre-thalamic relay nuclei from the UL and LL
2) Cell bodies are in the dorsal horn of the contralateral cord
3) fibers to the VPL
4) do decussate

Question 8

ventrotrigeminal tract

Answer 8

1) Carries pain, temp, crude touch, vibration, fine touch, proprioception from the contralateral face
2) cell bodies in the pontine sensory nuc. and spinal nucleus of V
3) sends fibers to the VPM
4) do decussate

Question 9

medial lemniscus

Answer 9

1) Carries vibratory sense, fine touch, and proprioception from the upper and lower limbs
2) cell bodies in the nucleus cuneatus and the nucleus gracilis
3) sends fibers to the VPL
5) do decussate