Ouch! Somatosensory system part 2 Flashcards
What are the two types of Adelta fibres?
Type 1 - noxious mechanical
Type 2 - noxious heat
Which neurotransmitter is released from nociceptive afferents?
Glutamate
When is glutamate released in nociceptive processing?
To signal acute or persistent noxious stimuli
Which areas of the brain are involved in pain interpretation?
Amygdala Cerebellum Brainstem Anterior cingulate cortex Insula cortex Prefrontal cortex Primary and secondary somatosensory cortex (SI and SII)
Which areas of the cortex are involved in pain?
Prefrontal cortex
Anterior cingulate cortex
Insula cortex
Primary and secondary somatosensory cortex (SI and SII)
What is the gate control theory of pain?
The body can inhibit primary afferent inputs before they are transmitted to the brain
Name two key structures of the brain involved in modulating pain signalling and state where they are
PAG; in midbrain
RVM - rostral ventral medulla
What happens in the dorsal horn to control pain/
Facilitation and inhibition of nociceptive processing
Which neurotransmitters are involved in pain modulation? State what they do
Serotonin - increase sensitivity to pain
Noradrenaline - dampen down pain
What are the two types of pain that people feel?
Nociceptive and neuropathic
Explain chronic pain
Tissue damage releases a variety of substances, including cytokines, which (in addition to promoting healing), modulate the excitability of nociceptors, making them more sensitive to further stimulation at a lower threshold.
C - fibres become sensitive in periphery
Adelta fibres become sensitive in dorsal horn
What is hyperalgesia and what are the two types?
Increased pain to a normally painful stimulus
Primary - at area of stimulus
Secondary - pain around area of stimulus
What is allodynia
Pain from an innocuous stimulus
What can be used to test pain?
Quantitative sensory testing
What was the result of trying to use SSRIs and SNRIs?
Low analgesic activity - useless seeing as it’s now been discovered the serotonin facilitates pain?
