Pain and Temperature Transmission Flashcards
what are nociceptors?
free nerve endings located in skin, bone, joints and blood vessels that detect pain transmission
what are thermoreceptors?
free nerve endings in the skin that respond to warmth or coolness
what is the type of stimulus and temperature range for the TRPV2 receptor?
- noxious heat
- above 125 F
what is the type of stimulus and temperature range for the TRPV1 receptor?
- heat, capsaicin
- above 109 F
what is the type of stimulus and temperature range for the TRPV3 receptor?
- warmth
- above 88 F
what is the type of stimulus and temperature range for the TRPV4 receptor?
- warmth for internal body temperature of blood (found only in hypothalamus and spinal cord)
- above 77 F
what is the type of stimulus and temperature range for the TRPM8 receptor?
- coolness: menthol or mint
- below 82 F
what is the type of stimulus and temperature range for the TRPA1 receptor?
- noxious cold
- below 64 F
what is physiological (nociceptive) pain?
the neural processes of encoding and processing noxious stimuli
what is neuropathic (intractable) pain?
result from injury to the peripheral or CNS that causes permanent changes in circuit sensitivity and CNS connections
list the steps of the somatosensory anteriolateral pathway
dorsal root ganglion —–> dorsal horn —> substantia gelatinosa —–> decussation via the anterior white commissure —-> anteriolateral corner of spinal cord —-> thalamus —–> ventral posteriorlateral nucleus ——> primary somatosensory cortex, cingulate cortex or insular cortex
what type of information does the anterior cingulate cortex process?
emotional learning
what type of information does the insula process?
self awareness, sense of self in pain, sense of visceral pain (gastric distention)
what type of information does the prefrontal cortex process?
anticipation of pain
what type of information does the periaqueductal grey process?
important sites of endogenous pain inhibition
where does the periaqueductal grey (PAG) project to in a descending pathway?
brain stem regions like the locus coeruleus, rostral ventromedial medulla and raphe nucleus
what is neuropathic pain?
altered physiology of touch and pain processing caused by damage or disease to the nervous system
what is allodynia?
pain produced by normally non-painful stimuli
what is hyperalgesia?
heightened pain response to a painful stimulus
what is peripheral sensitzation?
a reduction in threshold and an increase in responsiveness of the peripheral ends of nociceptors
what is central sensitization?
increase in the excitability of neurons within the central nervous system either due to peripheral or central nerve damage and inflammation
