Week 5: Pain concepts and assessment Flashcards
Related Pathways for different classifications and types of pain mechanism
Nociceptive = tissue
* Somatic structures (skin, muscles, connective tissue,
bones, joints)
* Visceral structures (visceral organs such as liver, gastro‐
intestinal tract).
Neuropathic = nerve
Afferent pathways
nociceptors (pain receptors)
afferent nerve fibres
spinal cord network
CNS pathway
the limbic system
* reticular formation
* thalamus
* hypothalamus
* cortex
Efferent pathways
reticular formation
* midbrain
* substantia gelatinosa in dorsal horn
transduction
conversion of mechanical, chemical and thermal stimulus into neuronal action potential to release of substances and a change in the charge released along the neuron membrane via transfers of ions channels
Transmission
stimulated nocieptors transmit impulses to the CNS via sensory fibres
from injury site to spinal cord
spinal cord to brain stem & thalamus
thalamus to cortex & other brain structures
ascending = sensory
Complex transmission from periphery to dorsal
root of spinal cord
o Terminate in dorsal horn
o Signals communicate with local interneurons
o Neurons with long axons ascend to brain
descending = motor
- Can be modulated
o Chemical substances
o Gate theory
o Actions - Selective response to stimuli
Perception
in the brain nociceptors processed as pain
Modulation
neurons originating in the brain stem descend to the spinal cord and release substances that change and inhibit nociceptive impulses
Gate theory
- Gate theory: tactile non‐noxious stimuli inhibits pain signal
transmission
Somatoform pain disorder
Pain caused, increased, or prolonged by mental,
emotional, or behavioural factors
Breakthrough pain
Sudden onset
* Short duration
* Unresponsive to normal pain management
Intractable pain
- Pain that is not relieved by ordinary
medical, surgical or nursing measures.
Phantom pain
Pain felt in a body part that is missing
