Term
| What are the 4 encapsulated nerve endings? |
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Definition
| Meissner's corpuscle, Merkel's disc, Pacinian corpuscle, Ruffini's ending |
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Term
| What type of nerve endings sense pain, temperature, crude touch? |
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Definition
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Term
| T/F: Free nerve endings have a low threshold for APs |
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Definition
| False (requires a lot of stimulus to perceive pain) |
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Term
| What stimulus are Ruffini's endings primed to respond to? |
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Definition
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Term
| What type of stimulus are Meissner's corpuscles designed to respond to? |
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Definition
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Term
| What stimulus are Merkel's discs primed to respond to? |
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Definition
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Term
| What stimulus are Pacinian corpuscles primed to respond to? |
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Definition
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Term
| Rank encapsulated nerve endings from small receptor field to large |
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Definition
| Alphabetical: Meissner-Merkel-Pacinian-Ruffini |
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Term
| Adaptation speed of Meissner? |
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Definition
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Term
| Adaptation speed of Merkel? |
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Definition
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Term
| Adaptation speed of Pacinian? |
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Definition
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Term
| Adaptation speed of Ruffini? |
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Definition
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Term
| What is the function of A-delta nerve fibers? |
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Definition
Respond to intense mechanical or mechano-thermal stimuli
Fast |
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Term
| Function of dorsal column medial-lemniscal pathway? |
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Definition
| Sense touch, pressure, proprioception, visceral pain |
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Term
| Where does the sensory information decussate (cross over) in the dorsal column medial-lemniscal pathway? |
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Definition
| Gracilis & cuneatus nuclei of the medulla |
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Term
| Where is the 3rd order cell of the DCML pathway? |
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Definition
| VPL (ventral posterolateral nucleus) of thalamus |
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Term
| Where does info in the spinothalamic pathway (pain, temp) cross over? |
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Definition
| At the spinal segmental level where the DRG axon arrives |
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Term
| Where is the second order cell of the spinothalamic pathway? |
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Definition
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Term
| What is the function of the C fibers? |
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Definition
Respond to mild thermal, chemical, mechanical stimuli
Unmyelinated- slow |
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Term
| What are the functions of the two vanilloid pain receptors? |
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Definition
VR-1 (or Transient Receptor Potential V1): sensitive to heat and capsaicin. A-delta and C fibers
VR-2 (TRPV2): just sensitive to heat. Only C fibers |
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Term
| What are the types of pain receptors? |
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Definition
Transient receptor potentials (TRPs)
Acid Sensing Ion Channels (ASIC)
NAv1.7
NAv1.8 |
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Term
| What is the underlying mechanism of central sensitization? |
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Definition
| Neurons in the dorsal horn that were recently stimulated have a lower threshold to be stimulated again |
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Term
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Definition
| Induction of pain by innocuous stimulus |
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Term
| T/F: C fiber stimulates inhibitory interneuron, reducing pain response |
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Definition
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Term
| T/F: A-beta fiber stimulates inhibitory interneuron, reducing pain response |
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Definition
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Term
| Pathway from pain to prostaglandins? |
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Definition
| C fibers activated -> release of glutamate and substance P -> rise in intracellular Ca++ -> activation of phospholipase A2 -> increased arachidonic acid -> COX pathway -> prostaglandins |
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