2A. Nociception Flashcards
Is the body’s response to a noxious stimulus and pain is how we respond to that stimulus
Nociception
Separate system for the Body using ___________ nerves, Spinothalmic tract
Spinal
Separate system for Head using ________ nerves, Quintothalamic tract
Cranial
Spinal reflex arcs for nociception
- Direct synapse of sensory fiber with Motor neuron
monosynaptic
Spinal reflex arcs for nociception
- interneurons in the reflex arc
Polysynaptic
Relay of nociception to higher centers: Spinothalamic Tract
(classic pathway in primates is shown)
- DRG
- axons ascend or descend a few segments forming the dorsolateral fasciculus (known as Lissaur’s Tract)
1st neuron
Relay of nociception to higher centers: Spinothalamic Tract
(classic pathway in primates is shown)
- dorsal gray horn spinal cord
- axons immediately cross and ascend contralateral in the ventrolateral funiculus as the spinothalamic tract
2nd neuron
Relay of nociception to higher centers: Spinothalamic Tract
(classic pathway in primates is shown)
- ventral caudal lateral nucleus of the thalamus VCL
- axons contribute to formation of Internal Capsule ascend to appropriate part of cerebral cortex
3rd neuron
In animals the Spinothalamic Tract is _________________ and _____________ with many synapses
bilateral, diffuse
Nociception participates in a localized _________ activity where we can assess specific segments of the cord or that information if it is given a strong enough stimulus can also then be ________________ to the higher levels for the Conscious perception of pain
reflex, relayed
Cranial Reflex Arc: Quintothalamic Tract
- Trigeminal ganglion
- axons ascend and descend a short distance forming the spinal tract of the trigeminal nerve
1st neuron
Cranial Reflex Arc: Quintothalamic Tract
- location depends on the modality of sensation: pontine sensory nucleus: mechanical type of sensation spinal nucleus of the trigeminal nerve: thermal type of sensation
- axon synapses in the brainstem on motor nuclei of appropriate cranial nerves
2nd neuron
GSA function in the head and face region that is served by cranial nerve # _________
V
Cranial Reflex Arc: Quintothalamic Tract
- any motor neuron of the appropriate cranial nerve
- axon leaves the brainstem through a cranial nerve to reach the peripheral target
3rd neuron
Mesencephalon =
Midbrain
Metencephalon =
pons
Myelencephalon =
Medulla
First order neurons in the quintothalamic tract are located in the:
Trigeminal Ganglion
Pontine sensory nucleus: _____________ type of sensation
mechanical
Spinal nucleus of the trigeminal nerve: _____________ type of sensation
Thermal
Quintothalamic tract for Relay to higher centers
- Trigeminal ganglion
- axons ascend and descend a short distance forming the spinal tract of the trigeminal nerve
1st neuron
Quintothalamic tract for Relay to higher centers
- location depends on modality of sensation: Pontine Sensory nucleus: Mechanical type of sensation
Spinal nucleus of the Trigeminal nerve: Thermal type of sensation
- axons immediately cross to the opposite side and ascend contralaterally as the Trigeminal Lemniscus
2nd neuron
Quintothalamic tract for Relay to higher centers
- ventral caudal medial nucleus of the thalamus VCM
- axons contribute to the formation of the Internal Capsule and synapse in the appropriate part of the Cerebral Cortex
3rd neuron
