Pain Integ Flashcards
An unpleasant sensory or emotional experience
pain
Perception of pain is a product of
Brain’s Abstraction and elaboration of sensory input
T/F activation of nocieptors does not necessarily lead to expereince of pain
t (pain can be perceived without activation of nociceptors, ex: phantom limb pain, thalamic pain syndrome)
What are the 2 clinical states of pain
- Physiological (nociceptive) -somatic, viseral
2. Neuropathic (intractable)0 deafferentation, sympathetic, peripheral
Nocioceptor (free nerve endings):
type mechanical activated by
Strong stimuli such a pinch, sharp object, Adelta
Thermal nocicpetors
noxious heat or cold, A delta
Polymodal nociceptors activiated by
mechanical, noxious heat, cold, irritant
NON MYELINATED C FIBERS
Deep, lancinating pain and carry vibratory signals, what fibers are these?
A-beta
Large somatic fibers having primary connections to cortical brain regions, fibers convey sharp, lancinating, easily localized pain signals.
A-delta
Which fibers are more primitive and slow conducting, generates more generalized dull, burning and aching pain sensation
C-Fibers
What is released by free nerve endings?
substance P
Besides cell injury, what is released from plateletes and damaged endothelial cells that activate nocicpetors?
Serotonin
Voltage gated channels are concentrated in the myelin sheath (nodes of Ranvier) of somatic nerve fibers, but are more evenly distrubited by
A-fibers
Unmyelinated C-fibers
Mast cell release what to induce vasodilation
histamines
Hot senation, slow pain, generalized touch afferent transmission, spinal laminas 1 and II
C-fibers
Cold sensation, fast pain, localized touch
A delta (spinal laminas I and 5)
Any damage to wiring along the neural pathway can be thought of as “static” alters the neural signal and is then perceived as pain
Neurogenic or neuropathic pain
At the end of the neural pathway whwere signals are interpreted, if central neurons are not working right, brain perceives pain
Central pain
Pain usually following stroke in the ventral basal thalamus. Rearragement of local circuit leads to excruciating pain
thalamic pain
Widespread damage and/or severe causal factors may cause more than one aspect of the pain percetion pathway to malfunction
CRPS
RUbbing skin near the site of injury to feel better or the use of TENS is example of
the gate theory of pain.
pain stimulus formt he body periphery is carried by A-delta and C-fibers to the dorsal horn of the SC
the Gate is located in the substantia gelatinosa of the DH it can facilitate or inhibit the progression of the nerve impulses through the CNS.
Gait theroy of pain
Summation of signals can cause
hyperexcitabiloity
occurs with continued moderate to severe pain. This creates a pain intensity that is greater than expected for the stimulus. therefore, the pain response is greatly enhanced when ___occured.
wind-up
What is the result of moderate to severe pain that last fro more than 24 hours
neuroplasticity
4 stages of nociception transmission
- Tranduction-noxious stimuli converts energy into a nerve impulse
- Transmission-neural pain signal moves from periphery to SC and brain
- Perception-how higher centers interpret pain
- Modulation-facilitation and inhiborty reponse
Substance P
Bradykinin
- C fibers/free nerve ending release
- Inflammatory response