Lecture 17, 18: Pain Flashcards
Discriminative pain
Ability to perceive and localize
Affective pain
Behaviors and emotions that affect mood and motivation
Pain information is carried in which spinal tract? Which fibers? What thalamic nuclei?
Spinothalamic; Ad and C fibers; VPL and VPM (face)
Affective pain nuclei in pons
Parabrachial nucleus (ACh cells)
Affective pain nuclei in midbrain
Periaquaductal gray
Affective pain nuclei in thalamus
VM and MD (recieves a lot of limbic information, relays to PFC)
Affective pain nuclei in forebrain
Amygdala (fear), globus pallidus (mediates decision making)
Affective pain nuclei in hypothalamus
VMH
MD projects to…
Cingulate (and PFC)
VM projects to…
S1 and insula
Limbic system contributes what to pain? What structures?
Emotional content; amygdala/cingulate
Motor/cognitive systems contribute what to pain? What structures?
Motivation; GP, insula, cingulate, S1
Hypothalamus contribute what to pain? What structures?
Generation of appropriate beavhiors to threats; VMH
Descending systems contribute what to pain? What structures?
Transmission of nociceptive info back down to dorsal horn of spinal cord; amygdala, VMH, PAG, rostroventral medulla (parabrachial, LC, raphe)
What structure directly projects to the descending systems of the spinal cord?
PAG
Raphe and LC nuclei project to what kind of dorsal horn neuron? What do these projects to? Effect?
Local circuit inhibitory endogenous opioid neurons; Ad or C axons AND dendrites of neurons rising up the spinothalamic tract; diminish pain signal
General types of pain disorders (4)
Nociceptive, inflammatory, dysfunctional, neuropathic
Nociceptive pain
Physiological pain produced by noxious stimuli that achieves high-threshold nociceptor neurons, protective
What fiber mediates first pain? Second pain?
Ad; C
Why is visceral pain able to generate referred pain?
Cutaneous and visceral neurons carrying pain information converge on the same neuron in dorsal horn
Inflammatory pain; always require stimulus?
Pain hypersensitivty due to peripheral inflammation, adaptive and reversible (protects during healing); NO, pain at baseline AND a not necessarily a painful stimulus can worsen (allodynia and hyperalgesia)
Allodynia and how? (pathway)
Normally non-painful stimuli becomes painful (sunburn); Ab fibers and C fibers can both synapse on the same inhibitory local circuit neuron, which then synapses on spinothalamic system