Pain Flashcards
Know the role pain plays in the survival of the horse
Warn of impending or actual injury and to make us protect an injured part to prevent further damage
Differentiate between pain and nociception, where does each occur?
Pain – brain
Nociception – mechanoreceptors
Know 4 things needed for processing of nociception
- Noxious stimulus
- Receptor capable of detecting the stimulus
- Transmission to the brain
- Interpretation of the stimulus as pain
Does all nociceptive stimulation result in pain?
Depends on the individual and situation
Define nociception
The neuronal processes for the transduction, transmission, modulation, projection and central processing of actual or potentially tissue-damaging stimuli
Know three types of nociceptors
- Thermal
- Mechanical
- polymodal
Know the structure and speed of A delta fibers. What reaction do they stimulate?
thinly myelinated and transmit signals rapidly (faster than C fibers); responsible for quick onset of sharp pain that stimulates withdrawal reflex
Know the structure and speed of C fibers. What sensation do they convey?
Unmyelinated; slower than A delta; responsible for second pain; dull throbbing or burning pain
Define persistent pain
Continuing pain from damaged tissue
Define chronic pain
Still present after tissue is healed
Define nociceptive pain
Direct activation of nociceptors from ongoing tissue damage, such as inflammation following injury
Define neuropathic pain
Due to damage to the nerves themselves
Define hyperalgesia
Exaggerated or prolonged response to pain
Define allodynia
Stimuli normally not painful becomes painful
Define maladaptive pain
Pain that is disconnected from noxious stimulus
Define central sensitization
Increased responsiveness of the CNS to stimuli that is normally below threshold
Define neuronal wind-up
C fibers fire repeatedly, as with severe persistent injury or with maladaptive pain, the response form the dorsal horn cells increases.
Define viscero-somatic pain
Pain from the surface of the body can have symptoms of visceral pain. Pain from the viscera can lead to a predictable pattern of pain on the surface of the body.
Define neurogenic inflammation
Inflammation mediated by substance P and other chemicals released by neurons
Know three areas of the brain that receive nociceptive input
Thalamus, limbic system, hypothalamus
Give a simple description of the Gate theory
Neurons open the gate for transmission of nociception to the cortex and non-nociceptors close it
How does rubbing or shaking an injured part help decrease pain?
It stimulates larger diameter afferents, closing the gate for the slower conducting nociceptors
