Pain Flashcards
the definition of PAIN is
Unpleasant sensory & emotional experience associated w actual or potential tissue damage
Nociception = Pain T/F
F –> Only if higher centres decode the information as such
Process of Pain Perception
Transduction
Transmission
Perception
Modulation
what are the main types of fibres for pain perception?
Adelta and C-fibres
What fibres are faster in pain perception?
Adelta (very fast and myelinated)
C-fibres are myelinated T/F
F –> Very fine, unmyelinated and not very fast
The cells bodies of pain nerve fibres are located in
Dorsal Root Ganglia and Trigeminal
How many layers does the dorsal horn has?
6
which type of fibre only synapses with the most superficial layers?
C-fibres
Adelta fibres are not found in the palm of the hand T/F
F –> only C-Fibres are found in the palm of the hands
which type of fibre is responsible for sharp intense pain?
Adelta
Which type of brain pathway can increase/decrease pain sensation?
Descending pathways
Which areas of the brain are important in pain modulation?
Periaqueductal Grey (PAG) Rostroventral Medulla (RVM)
What is inflammatory pain?
Pain caused by inflammatory soup
what are some of the mediators found in the inflammatory soup?
Cytokine, Bradykinin, PGE2, ATP & Adenosin
Define Allodynia
Pain perception on normal stimuli
How is define the increased pain perception and response to normally painful stimulus?
Hyperalgesia
What are TRP channels and what do they mediate?
Transient Receptor Potential and mediate increased pain sensation by increasing membrane potential (allowing for activation at physiological temperature)
TRP1 agonist
Capsaicin
Areas in charge of perception of emotional pain?
Cingulate and pre-frontal cortex
what types of sensitisation can be found and how do they operate?
Central –> Makes CNS more sensitive
Peripheral –> Makes nerve more sensitive
2nd order neuron in the pain pathway goes to
Anterolateral System
how many pain fibres have higher cortex connections at each site?
5/10
What is maladaptive Pain?
pain produced without an underlying pathology or stimuli either due to poor regeneration of the fibre or due to unknown reasons
what are the 3 main types of pain?
Nociceptive
Inflammatory
Maladaptive
Neuropathic Pain is?
pain caused due to damage to the sensory pathway or the CNS structure in charge of processing pain
Example of dysfunctional pain?
Myalgia and migraines
What is dysfunctional pain?
Pain with no known cause
TRP channels allow for the entering of Ca or Na ions T/F
T
what is the Nocebo Effect?
hyperalgesia caused by expectation that relies on previous experience
example of nocebo effect?
pain felt on injections
What is Hypoalgesia?
Reduced pain sensation
What can be a cause (physiological) of hypoalgesia?
Release of endogenous pain modulators and activation of descending pathways
What is ‘Fear Behaviour’?
Hypoalgesia induced due to activation of the Sympathetic System
What mediates fear behaviour?
the Amygdala (desensitisation to pain through PAG)
what is the pathway followed by nociceptive pain?
1 Activation of pain fibre
2 travels to spinal cord
3 enters via dorsal root (cell body in dorsal root ganglia)
4 can decussate 1-2 levels above or bellow via the anterior white comissure
5 goes to higher cortical centres via the Antero-Lateral System
6 reaches the Thalamus on contralateral site to stimuli
7 to somatosensory cortex
How many neurons form part of the pain pathway?
3
Where do NSAIDs act in the descending pathway?
PAG
where do opioids act in the pain pathway?
PAG and RVM
Where to weed act in the pain pathway?
Rostroventral Medulla
How much heat can cause pain?
> 52 degrees
