Pain Processing Flashcards
What are the four types of mechanoreceptors (tactile receptors)?
Meissner corpuscles (40%),
Merkel cells (25%),
Ruffini corpuscles (20%),
Pacinian corpuscles (10-15%)
Which tactile receptor types are rapidly adapting? Which ones slowly?
slow: Merkel, Ruffini
rapid: Meissner, Pacinian
What is the somatosensory system?
In physiology, the somatosensory system is the network of neural structures in the brain and body that produce the perception of touch (haptic perception), as well as temperature (thermoception), body position (proprioception), and pain.
It is a subset of the sensory nervous system, which also represents visual, auditory, olfactory, and gustatory stimuli.
What is noiciception?
the perception of potentially harmful stimuli
Is pain coded in excessive action of somatosensory receptors?
No, in distinct perception and signaling pathway
Which receptor type is responsible for proprioception?
What is its corresponding axon type?
Muscle spindle;
Ia, II
Which receptor type is responsible for touch?
Merkel, Meissner, Pacinian and Ruffini
Which receptor type is only responsible for pain and temperature? And what is its corresponding axon type?
Free nerve endings;
Adelta (Ad)
Which receptor type is responsible for pain, temperature AND itch? And what is its correspoding axon type?
Free unmyelinated nerve endings;
C (fibers)
What are the stages of pain processing
- Transduction: conversion of nociceptive stimuli into electrical or chemical (i.e., neuronal) signals
- Transmission: Forwarding input to brain
- Modulation: Remodeling of noiciceptive information
What is the Transient receptor potential (TRP) family?
large group of pain receptors
-> mostly highly-selective Ca2+ channels which can be either open or closed (akin to other ionotropic receptors)
Subsets of pain receptors have divergent thresholds for…
thermal, chemical, or mechanical damage;
And also two different fiber types with different temporal dynamics and qualities of pain
Fibers conveying tactile information and proprioception ascend …?
Fibers conveying information concerning pain and temperature ascend …?
1= ipsilaterally
2= contralaterally
What are transient receptor protein (TRP) ion channels (that are selective for Ca2+) crucial for?
translation of noxious stimuli (temperature, chemicals) into neuronal signals
Is pain perception an objective representation of stimulus intensity or tissue harm?
No, it is a highly contextualized and modulated by top-down control, e.g. in the placebo effect
