Nociception and thermal sensation of CN V

Question 1

Where is the cell body located in the first order neuron?

Answer 1

Trigeminal ganglia

–located on the floor of the middle cranial fossa

Question 2

What type of fibers enter the spinal tract of the trigeminal nerve (V) and where do they enter?

Answer 2

Myelinated and unmyelinated fibers (A delta and C caliber)

—At the level of the middle pons

Question 3

The fibers of the first order neuron travel which way to synapse in the Spinal Trigeminal Nucleus?

Answer 3

Decend Ipsilaterally

Question 4

Where is the Spinal Trigeminal Nucleus located?

Answer 4

In the Medulla

Question 5

Where is the cell body of the 2nd order neuron located?

Answer 5

In the Spinal Nucleus of V (Spinal Trigeminal Nucleus)

Question 6

The Spinal Trigeminal Nucleus has how many divisions? How are they organized

Answer 6

Three

—topographical pattern with respect to the distribution of incoming sensory information

Question 7

What other information does the Spinal trigeminal nucleus receive and where from?

Answer 7

Somatosensation from branches of CN VII, IX and X from skin areas around the ear

Question 8

Fibers of the 2nd order neuron cross the midline and line up where?

Answer 8

Adjacent to the cervial component of the medial lemniscus

Question 9

The tract of the 2nd order neuron after lining up adjacent to the cervical component of the medial lemniscus travels where?

Answer 9

Ascends contralatearlly as the ventral trigeminal thalamic tract

Question 10

The Ventral Trigeminal Thalamic Tract ascends contralaterally to synapse where?

Answer 10

In the Ventral posteromedial thalmic nucleus (VPM)

Question 11

The 3rd order neuron is located where?

Answer 11

In the Ventral posteromedial thalamic nucleus (VPM)

Question 12

The Ventral posteromedial thalamic nucleus (VPM) is what divison of the VPL

Answer 12

Medial

Question 13

Fibers of the VPM neurons leave where and travel where?

Answer 13

Leave the thalamus and

—Ascend to the cortex in the Posterior limb of the internal capsule

Question 14

Where do fibers of the VPM neurons terminate or synpase

Answer 14

In the face area of Primary Somatosensory Cortex

Post central gyrus; Boradmann’s area, 3, 1, 2

Question 15

Trigeminal neuralgia or Tic douloureux are pathalogical conditions assoicted with the trigeminal nerve, they are marked by what?

Answer 15

Excruciating pain

Question 16

Pain from Trigeminal Neuralgia or Tic douloureux is set off by only mild stimulation, why?

Answer 16

Compression of the nerve by swelling of the nerve sheath

Question 17

How is surgically cutting the decending fibers in the spinal tract of V possible?

Answer 17

Due to the topographical distribution of the fibers carrying the pain sensation, and the anatomical location on the lateral surface of the caudal medulla

Question 18

What drastic measures may need to be taken to relieve pain from Trigeminal Neuralgia or Tic douloureux

Answer 18

Surgically cutting the descending fibers in the Spinal tract of V