Neuroanatomy of Pain pathways Flashcards
Components of pain pathways
- Detection of painful stimuli
2.Transmission in spinal pathways
- Brain regions involved in experience of pain
Where does pain arise?
-a conscious, complex experience
How is the nervous system plastic?
-strength of synaptic connections in CNS changeable
-pain pathways also plastic
Phases of nociceptive pain
1.Transduction
2.Conduction
3. Transmission
4.Modulation
5. Perception
Transduction phase of nociceptive pain
proteins and voltage gated ion channels that convert thermal, mechanical, or chemical energy into an AP
Conduction phase of nociceptive pain
AP moved through pain fibres to depolarize the pre-synaptic terminal
Transmission phase of nociceptive pain
Post synaptic membrane activated and signal is relayed in spinal cord
Modulation phase of nociceptive pain
An adaptive process involving both excitatory and inhibitory mechanisms (peripheral and central modulation)
Perception phase of nociceptive pain
Integration of sensations, emotions, and cognition that results in a unique perception of pain
Where is nociceptive information relayed?
-sensory (afferent) information is relayed via ascending pathways through white matter tracts to the brain
Sensory neurons
-proprioception- detects where they are in space
-exteroception- detects touch, pressure, temp,
-nociception- detects noxious stimulus
Differences with nociceptors compared with other sensory neurons
-smaller in size
-more numerous
What tissues and organs do nociceptors supply?
1.Head: meninges, blood vessels, cornea, tooth pulp
2.Skin: epidermis, dermis
3. Muscle: fascia, tendons
4. Bone: periosteum, perivascular
5. Joints: synovium, ligaments, periosteum
6. Viscera: cardiac muscle, GI, urogenital
Where is there no nociceptors?
Brain!
Reason why brain surgeries are conducted when individual awake.
What noxious stimuli do nociceptors detect?
-Mechanical stimuli
-Thermal stimuli
- Chemical (H+) stimuli
