Ascending tracts- Trigeminal tract

Question 1

Where do all trigeminal tracts start?

Answer 1

Trigeminal ganglion

Question 2

What is the pathway for proprioceptive tactile vibration information?

Answer 2

1) Trigeminal ganglion
2) Principal sensory nucleus in the mid pons
3) 2nd order neuron leaves PSN
4) Crosses over to contralateral side and joins anterior trigeminothalamic tract
5) Synapses onto VPM of thalamus
6) 3rd order neurons go from VPM to Postcentral gyrus

Question 3

What is the pathway for pain and temp V1 fibers?

Answer 3

1) TG
2) Spinal trigeminal tract
3) Inferior portion of Spinal trigeminal nuclei in C1-C3
4) Exit STN via 2nd order neuron
5) Crosses over to contralateral side and joins anterior trigeminothalamic tract
6) Synapses at VPM of thalamus
7) 3rd order neurons go from VPM to Postcentral gyrus

Question 4

What is the pathway for pain and temp V2 fibers?

Answer 4

1) TG
2) Spinal trigeminal tract
3) Middle portion of Spinal trigeminal nuclei in C1-C3
4) Exit STN via 2nd order neuron
5) Crosses over to contralateral side and joins anterior trigeminothalamic tract
6) Synapses at VPM of thalamus
7) 3rd order neurons go from VPM to Postcentral gyrus

Question 5

What is the pathway for pain and temp V3 fibers?

Answer 5

1) TG
2) Spinal trigeminal tract
3) Rostral portion of Spinal trigeminal nuclei in C1-C3
4) Exit STN via 2nd order neuron
5) Crosses over to contralateral side and joins anterior trigeminothalamic tract
6) Synapses at VPM of thalamus
7) 3rd order neurons go from VPM to Postcentral gyrus