Unit 2_Pain Flashcards
What is an unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage?
Pain
Pain is always a _________ ________that is influenced to varying degrees by biological, psychological, and social factors.
personal experience
Pain and ________ are different phenomena. Pain cannot be inferred solely from activity in sensory neurons.
nociception
Through their life experiences, individuals learn what?
the concept of pain
A person’s report of an experience as pain should be what?
respected
Although pain usually serves an adaptive role, it may have _______ ________ on function and social and psychological well-being.
adverse effects
What is only one of several behaviors to express pain?
Verbal description
What type of pain fibers presents as fast pain = pinprick, extreme cold temp?
Type A Delta
What type of pain fibers presents as slow pain, “dull” “burning”, hot temp?
Type C
What type of pain fibers react to mechanical (squishing your finger, extreme temperatures) stimuli (–> Na+ influx into cell –> action potential) –> A Delta fibers?
Nociceptors
What results in pain releases chemicals (e.g., H+, K+, histamine) –> C fibers?
Tissue damage
What type of are Merkel’s discs, peritrichial, and most important free nerve endings –> A Delta + C fibers?
crude touch + superficial pressures
What makes the difference in transduction speed?
Myelination
We experience adaptation from acute (sharp, short-lasting) to _______ pain (longer lasting, vanishes when the injury has healed).
persistent
Pain can be attributed to any what (example spicy food)?
sensation
What pathway does pain travel in?
ALS
Pain from the body will relay through what?
the ventral posteriolateral thalamic nuclei
Pain from the face will relay through what?
the ventral posteriomedial thalamic nuclei
Pain from the face enters what structure and immediately crosses?
The medulla
In the cortex, pain will be perceived on what side?
Contralateral
What initiate pain responses (autonomic and endogenous)?
Pain from the spinoreticular and spinomesencephalic pathways
Approximately what percentage of afferent C fibers synapse in the reticular formation, which alerts almost the entire cerebral cortex?
85%
What carries information from the spinal cord to the parabrachial nucleus of the dorsolateral pons?
spinoparabrachial tract
What do the spinoparabrachial tract neurons target, including the insular and anterior cingulate cortex, which process emotional features of the pain experience?
limbic forebrain regions
What is an inflammatory response to tissue damage?
NOCICEPTIVE STIMULI
What are released by damaged tissues augment the response of nociceptive fibers (chemically)?
Substances
What cause the release of peptides and neurotransmitters that further inflammatory responses?
Nociceptors
What is sensation in areas associated with tissue damage are perceived as more painful than if tissue was not damaged?
Hyperalgesia
What is sensation that is not painful is perceived as painful due to peripheral sensitization?
Allodynia
What in the dorsal root ganglia send their axons via the dorsal roots to terminate in the dorsal horn of the spinal cord?
Afferents branch and course for several segments up and down the spinal cord in Lissauer’s tract*, giving rise to collateral branches that terminate in the dorsal horn.
Second-order neurons in the dorsal horn send their axons (black) across the midline to ascend to higher levels in the anterolateral column of the spinal cord.
Primary afferents in the anterolateral tract
What type of fibers terminate in Rexed’s laminae I and II of the dorsal horn, while A Beta fibers terminate in laminae I and V? The axons of second-order neurons in laminae I and V cross the midline and ascend to higher centers.
Type C fiber
What accounts for the fact that activation of low-threshold primary afferent fibers can attenuate pain?
The two classes of sensory fibers also terminate on the inhibitory interneurons; the C fibers indirectly inhibit the interneurons, thus increasing the activity of the projection neurons (thereby “opening the gate”), whereas the Aβ fibers excite the interneurons, thus suppressing the output of the projection neurons (and “closing the gate”).
Gate Control Theory - Central Modulation
What kind of pathway arises in the nucleus raphe magnus and projects to the dorsal horn of the spinal cord as part of the ENDOGENOUS OPIODS EFFERENT PATHS?
A serotonergic pathway
What system arises in the locus coeruleus and other nuclei in the pons and medulla as part of the ENDOGENOUS OPIODS EFFERENT PATHS?
A noradrenergic system
In the spinal cord, what descending pathways inhibit nociceptive projection neurons through direct connections as well as through interneurons in the superficial layers of the dorsal horn? These sites express endogenous opioids and are the targets for drugs like natural or synthetic opioids (e.g., morphine).
A serotonergic pathway
A noradrenergic system
Both the serotonergic nucleus raphe magnus and noradrenergic nuclei receive input from neurons in what region?
in the periaqueductal gray region
What decrease the duration of the postsynaptic potential, probably by reducing Ca2+ influx, and thus decrease the release of transmitter from the primary sensory terminals? In addition, opiates hyperpolarize the dorsal horn neurons by activating a K+ conductance and thus decrease the amplitude of the postsynaptic potential in the dorsal horn neuron.
Opiates
What forebrain areas, including the anterior cingulate cortex (ACC), other frontal cortical areas, the hypothalamus (H) and central nucleus of the amygdala project to the midbrain periaqueductal grey (PAG), which can be thought of as a main output pathway of the limbic system?
Limbic
The separate components that convey, modulate, and control pain do not act in what?
Isolation
Interconnections happen between what of the cortex and areas that control emotions and the somatosensory system?
regions
What in the hypothalamus activate the autonomic nervous system that controls the body’s responses to pain, such as grimacing, tearing, or sweating?
Neurons
What can be an abnormal response to a lesion or an intervention and is a condition in which pain is experienced every day for three months or longer and lasts beyond the expected period of healing. It is referred to as chronic pain?
Severe, long-lasting pain (this does not include the normal persistent pain response that disappears when an injury has healed)
What show altered neural activity of many areas in the pain matrix, e.g., the insula cortex (Ins), prefrontal cortex (PFC), anterior cingulate cortex (ACC), and amygdala (Amg) in patients with chronic pain?
Imaging studies with magnetic resonance tomography (MRI)
What are 2 aspects to the pain experience?
The spinothalamic tract
The affective (emotions) and motivational aspects of second pain
What conveys signals that mediate the sensory discrimination of first pain?
The spinothalamic tract
What are mediated by complex pathways that reach integrative centers in the limbic forebrain?
The affective (emotions) and motivational aspects of second pain
What is a positive physical or psychological change that occurs after taking medication without an active ingredient?
The placebo effect
What is a negative physical or psychological change that occurs after taking medication without or without and active ingredient?
The nocebo effect
