L10 - Pain Flashcards
Why is pain essential for survival?
Pain is a normal, protective mechanism that alerts the body to potential danger, helping us avoid harm and respond to injuries.
Is pain a direct sensation from the body?
No, pain is a perception. Although people often regard pain as a sensation, it is how the brain interprets nerve signals that determine whether we perceive pain or not.
What are nociceptors, and do they send pain signals?
Nociceptors are nerves that send danger signals, not pain signals. The brain interprets these signals to decide whether to perceive pain.
What are the three types of nerve endings and how do they relate to pain?
- Heat-sensitive: Respond to extreme temperatures (too hot/cold).
- Touch-sensitive: React to excessive pressure.
- Chemical-sensitive: Triggered by substances like wasp stings or nettles.
All three can lead to the perception of pain.
How was pain understood 300 years ago?
It was believed that pain signals traveled from the skin to a specific “pain center” in the brain, like a fuse wire carrying a signal. This theory has since been challenged.
How does phantom limb pain challenge old theories of pain?
Phantom limb pain occurs when pain is felt in a limb that no longer exists, showing that pain is not simply a signal sent from a body part but a perception created by the brain.
Why does the pain of a heart attack sometimes radiate to the left arm?
Referred pain can occur when pain from one area of the body (like the heart) is perceived in a different region (such as the left arm) due to the way the brain processes nerve signals.
How does the International Association for the Study of Pain (IASP) define pain in 2020?
Pain is defined as “an unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage.”
What additional elements does the Williams and Craig definition of pain include?
They propose that pain is a distressing experience involving sensory, emotional, cognitive, and social components, highlighting the multidimensional nature of pain.
What factors contribute to the variability in how patients experience pain?
Pain is influenced by the biopsychosocial model, meaning a patient’s emotional, cognitive, social, and physical context all affect their perception of pain.
How does inflammation influence pain perception?
Inflammation lowers the firing threshold of nociceptors, making even mild stimuli feel painful. This heightened sensitivity is known as peripheral sensitization.
What is the difference between acute and chronic inflammation in relation to pain?
Acute inflammation: Short-term, often related to injuries like sprains.
Chronic inflammation: Longer-lasting, potentially due to pathological conditions or delayed healing processes, such as stress or metabolic disorders.
How does stress affect the healing process and pain perception?
Stress can prolong healing and contribute to chronic pain by maintaining an inflammatory response, as seen in conditions like diabetes or metabolic syndrome.
What is the basic premise of the pain gate theory?
The pain gate theory suggests that non-painful stimuli can “close the gate” to painful signals in the spinal cord, preventing those signals from reaching the brain and reducing the perception of pain.
How do myelinated Aδ fibers differ from unmyelinated C fibers in transmitting pain?
Aδ fibers: Fast-conducting, myelinated fibers that provide sharp, localized pain information.
C fibers: Slow-conducting, unmyelinated fibers that give rise to dull, diffuse pain sensations.
What role do Aβ fibers play in the pain gate theory?
Aβ fibers carry information about non-painful stimuli like touch and pressure. Stimulating these fibers can inhibit nociceptive signals (danger signals), effectively “closing the gate” and reducing pain.
Does the pain gate theory explain all types of pain?
No, the pain gate theory primarily explains acute pain. Chronic pain, especially neuropathic pain, does not always respond to this mechanism and involves more complex physiological processes.
What health conditions may influence pain perception due to physiological mechanisms?
Conditions like diabetes, obesity, hypertension, vitamin D deficiency, rheumatoid arthritis, and metabolic syndromes can all alter pain perception through their effects on the nervous system and inflammatory processes.
How does the biopsychosocial model relate to pain?
This model considers how biological factors (e.g., nerve damage), psychological factors (e.g., stress, emotions), and social factors (e.g., environment, support) all influence an individual’s experience of pain.
What distinguishes neuropathic pain from other types of pain?
Neuropathic pain is caused by damage to or dysfunction of the nervous system, and it often presents as burning, tingling, or shooting pain. It involves different physiological mechanisms than nociceptive pain.
How does peripheral sensitization occur in the context of pain?
Peripheral sensitization occurs when inflammation lowers the threshold of nociceptors, making them more sensitive to stimuli, leading to heightened pain responses even to normally non-painful stimuli.
