Sensory Systems

Question 1

CNV Fine touch and proprioception

Answer 1

1: Trigeminal nucleus to Chief Sensory Nucleus
2: Decussate and ascend Ventral Trigemino-Thalamic Tract to VPM
3: VPM to primary somatosensory cortex

Question 2

CNV Crude touch, pain, temperature

Answer 2

1: Trigeminal nucleus, descends spinal trigeminal tract in brainstem, to spinal trigeminal nucleus
2: Decussate and ascend Ventral Trigemino-Thalamic Tract to VPM
3: VPM to primary and secondary somatosensory cortex

Question 3

CNV Proprioception (nonconscious)

Answer 3

1: Mesencephalic Nucleus (**Not peripheral)
- Peripheral Axon–> Mesencephalic tract, through trigeminal ganglion
- Central Processes –> VPM, Trigeminal motor nucleus, cerebellum (pathway poorly understood)

Question 4

Spinomesencephalic Tract

Answer 4

Involved in orienting head and eyes toward noxious stimulus

Activates descending pain control system

Question 5

Spinoreticular Tract

Answer 5

Commands and attention and disrupts sleep

Question 6

Spinolimbic Tract

Answer 6

Emotional response to pain

Question 7

CNVII Somatosensation

Answer 7

1: Geniculate Ganlion
2: Spinal Trigeminal Nucleus –> Cross and ascend in ventral trigeminothalamic tract
3: VPM

Question 8

CNIX Somatosensation Pathway

Answer 8

1: Inferior and superior glossopharyngeal ganglia
2: Spinal Trigeminal Nucleus –> Cross and ascend in ventral trigeminothalamic tract
3: VPM

Question 9

CNIX Somatosensation Coverage

Answer 9

Pharynx, middle ear, external ear, posterior 1/3 of tongue.

Question 10

CNVII Somatosensation Coverage

Answer 10

Small area near ear

Question 11

CNX Somatosensation Coverage

Answer 11

Pharynx, meninges, small region near ear

Question 12

CNX Somatosensation Pathway

Answer 12

1: Inferior and Superior Vagal Ganglia
2: Spinal trigeminal nucleus –> Cross and ascend in ventral trigeminothalamic tract
3: VPM

Question 13

Dorsal Spino-Cerebellar tract

Answer 13

Unconscious proprioception from LE
1: DRG –> Ascends in periphery of SC (dorsal lateral area)
Fibers remain ipsilateral the entire time
Enters cerebellum via inferior peduncle

Question 14

Ventral Spino-Cerebellar tract

Answer 14

Unconscious proprioception from LE

1: DRG –> Crosses and ascends contralaterally –> Pons –> Superior peduncle (recrosses first)

Question 15

Cuneo-cerebellar Tract

Answer 15

Unconscious proprioception from UE
1: DRG –> Ascend in periphery of SC (dorsal lateral area)
2: Fasciulus cuneatus
Fibers remain ipsilateral the entire time
Enters cerebellum via inferior peduncle

Question 16

Rostral Spino-cerebellar Tract

Answer 16

Unconscious proprioception from UE
1: DRG –> Ascends ipsilateral
Enters cerebellum via inferior and superior peduncles