Nociception and thermal sensation of CN V Flashcards
Where is the cell body located in the first order neuron?
Trigeminal ganglia
–located on the floor of the middle cranial fossa
What type of fibers enter the spinal tract of the trigeminal nerve (V) and where do they enter?
Myelinated and unmyelinated fibers (A delta and C caliber)
—At the level of the middle pons
The fibers of the first order neuron travel which way to synapse in the Spinal Trigeminal Nucleus?
Decend Ipsilaterally
Where is the Spinal Trigeminal Nucleus located?
In the Medulla
Where is the cell body of the 2nd order neuron located?
In the Spinal Nucleus of V (Spinal Trigeminal Nucleus)
The Spinal Trigeminal Nucleus has how many divisions? How are they organized
Three
—topographical pattern with respect to the distribution of incoming sensory information
What other information does the Spinal trigeminal nucleus receive and where from?
Somatosensation from branches of CN VII, IX and X from skin areas around the ear
Fibers of the 2nd order neuron cross the midline and line up where?
Adjacent to the cervial component of the medial lemniscus
The tract of the 2nd order neuron after lining up adjacent to the cervical component of the medial lemniscus travels where?
Ascends contralatearlly as the ventral trigeminal thalamic tract
The Ventral Trigeminal Thalamic Tract ascends contralaterally to synapse where?
In the Ventral posteromedial thalmic nucleus (VPM)
The 3rd order neuron is located where?
In the Ventral posteromedial thalamic nucleus (VPM)
The Ventral posteromedial thalamic nucleus (VPM) is what divison of the VPL
Medial
Fibers of the VPM neurons leave where and travel where?
Leave the thalamus and
—Ascend to the cortex in the Posterior limb of the internal capsule
Where do fibers of the VPM neurons terminate or synpase
In the face area of Primary Somatosensory Cortex
Post central gyrus; Boradmann’s area, 3, 1, 2
Trigeminal neuralgia or Tic douloureux are pathalogical conditions assoicted with the trigeminal nerve, they are marked by what?
Excruciating pain
Pain from Trigeminal Neuralgia or Tic douloureux is set off by only mild stimulation, why?
Compression of the nerve by swelling of the nerve sheath
How is surgically cutting the decending fibers in the spinal tract of V possible?
Due to the topographical distribution of the fibers carrying the pain sensation, and the anatomical location on the lateral surface of the caudal medulla
What drastic measures may need to be taken to relieve pain from Trigeminal Neuralgia or Tic douloureux
Surgically cutting the descending fibers in the Spinal tract of V
