Lecture 22 11/25/24 Flashcards
What are the general characteristics of pain?
-unpleasant and aversive sensation
-complex and multifactorial
-emotional, subjective, and individual
-associated with damages/possibility of damages to body
-modifies animal behavior and expressions
What are the characteristics of transduction?
-conversion of noxious stimuli into action potential
-occurs at level of nociceptors of primary afferent A-delta and C fibers
-site of peripheral sensitization
What is transmission?
propagation of action potential through first order neurons
What is the role of A-beta fibers?
-touch, vibration, pressure, and innocuous stimuli
-involved in allodynia and central/peripheral sensitization
What is the role of A-delta fibers?
strong, rapid, sharp, localized, acute pain
What is the role of C fibers?
slow, burning, diffuse, dull pain
What are the characteristics of modulation?
-process by which nociceptive signal is augmented or inhibited after first order neuron synapse with second order neuron in the dorsal horn of spinal cord
-central sensitization
What is the role of excitatory neuropeptides?
facilitate/amplify pain signals in ascending projection neurons
What is the role of inhibitory endogenous neuropeptides?
dampen nociceptive response through descending analgesic systems
What are the characteristics of projection?
-process of transporting nociceptive information from the spinal cord to the brain stem, thalamus, and cortex
-second order neuron sends information to brain stem and thalamus
What are the characteristics of perception?
-cortical interpretation of noxious stimulus
-cerebral cortex is also central analgesia system
-liberation of enkephalins, endorphins, and serotonin helps to decrease/abolish pain
What are the characteristics of adaptive pain?
-can be nociceptive or inflammatory
-high pain threshold
-acute pain
What are the characteristics of maladaptive/pathological pain?
-can be neuropathic or functional
-low pain threshold
-chronic pain
What are the characteristics of acute pain?
-abrupt, temporary, and predictable
-nociceptive or inflammatory
-physiological/adaptive/biological purpose
-alters animal’s behavior to be protective
What causes acute pain to stop?
-external stimulus is removed
-inflammation has resolved
-healing is achieved
What are the characteristics of chronic pain?
-beyond expected duration of disease process/injury healing
-neuropathic/dysfunctional
-no biological purpose or clear end point
-resistant to conventional analgesic therapy
-affects physical and emotional well being
-can be maladaptive
What are the characteristics of neuropathic pain?
-important primary lesion in nervous system
-persistent painful stimuli
-chronic pain
-neuropathic pain and underlying condition must be treated