Chapter 6_1 flashcards
(34 cards)
Pain: Definition (International Association for the Study of Pain)
An unpleasant sensory and emotional experience associated with actual or potential tissue damage.
Protective Mechanism Role of Pain
Allows the body to detect injury and enables the body to protect itself from more serious injury.
Epidemiology of Pain: General Impact
Most common symptom prompting medical attention; second leading reason for work absenteeism; significant healthcare costs and lost productivity.
Central Nervous System (CNS) Components in Pain Perception
Brain and spinal cord. Spinal cord’s substantia gelatinosa (H-shaped region in center) and dorsal horn (posterior region where sensory nerves enter) are key.
Afferent Neurons: General Role in Pain
Sensory nerves that carry pain, temperature, touch, proprioception, vibration, and pressure sensations from the periphery into the dorsal horn of the spinal cord.
Efferent Neurons: General Role in Pain Pathway
Motor nerves that exit the spinal cord through the ventral horn and extend to the muscles of the body, enacting motor activity (e.g., reflex response).
Nociceptors: Definition & Location
Specialized pain nerve fibers (afferent neurons) that respond to noxious stimuli. Found in skin, muscle, connective tissue, bone, circulatory system, and abdominal, pelvic, thoracic viscera.
Neurotransmitters: General Role in Pain Transmission
Excitatory or inhibitory chemical mediators released from one neuron to stimulate another. Involved in communication of nociceptive information in spinal cord and brain.
Endogenous Opioids: Definition, Examples, & Role
Natural analgesic neurochemicals that inhibit pain sensation. Examples: endorphins, enkephalins, dynorphins. Released by interneurons in spinal cord (stimulated by descending pathways from PAG & NRM in brainstem) to bind opioid receptors on incoming pain fibers.
Dermatomes & Myotomes: General Definitions
Dermatome: A skin area innervated by the sensory fibers of a single nerve root. Myotome: A group of muscles primarily innervated by the motor fibers of a single nerve root.
Gate Control Theory (Melzack & Wall, 1965): General Concepts
Pain is not necessarily proportional to tissue injury. Sensation travels both to and from the brain. Neural signals in spinal cord are influenced by other neurons (dampened or amplified) before reaching brain.
Neuromatrix Theory (Melzack, 1990): General Concepts
Emphasizes the brain’s influence in pain. Pain is a multidimensional experience (thoughts, past experiences, emotions, stress) produced from neurosignature patterns in a brain neural network (body-self neuromatrix). Brain can generate pain independently of sensory input.
Pain Assessment: Significance & Subjectivity
Pain is the fifth vital sign. It’s a subjective experience; patient’s report is primary. Pain behaviors differ and are not reliable indicators of intensity/quality.
OLDCART Mnemonic for Pain Assessment (Box 6-1)
Onset (When did it begin?), Location (Where?), Duration (How long?), Characteristics (What does it feel like?), Aggravating/Relieving factors (What makes it worse/better?), Associated symptoms, Treatment (What made it better?).
Pain Scales: Examples for Assessing Severity
McGill Pain Scale (quality & severity), Visual Analog Scale (VAS; 0-10), Wong-Baker FACES Scale (children, cognitive impairment), Critical Care Pain Observation Tool (CPOT) or FLACC (noncommunicative patients).
WHO Step Analgesic Ladder: General Principle
A stepwise approach for pharmacological pain management, starting with nonopioids, then weak opioids, then strong opioids, often with adjuvant medications. Can be used bidirectionally.
Major Classes of Pharmacological Pain Relievers
- Opioid analgesics. 2. Nonopioid analgesics (e.g., NSAIDs, acetaminophen). 3. Adjuvant medications (e.g., antidepressants, anticonvulsants).
Nonpharmacological Pain Management: General Concept & Examples
Methods used alone or with drugs for pain relief, often part of integrative medicine. Examples: Physiotherapy, occupational therapy, acupuncture, guided imagery, TENS, psychological counseling.
Key Term: Addiction
Primary, chronic, neurological disease with genetic, psychosocial, and environmental factors. Characterized by impaired control over drug use, compulsive use, continued use despite harm, and craving.
Key Term: Afferent Neuron
Sensory neuron that carries impulses (e.g., pain, touch, temperature) from the periphery into the central nervous system (spinal cord’s dorsal horn).
Key Term: Efferent Neuron
Motor neuron that carries impulses from the central nervous system (spinal cord’s ventral horn) to effector organs like muscles or glands.
Key Term: Gate Control Theory
Theory that pain signals are modulated by a “gate” in the spinal cord (interneuron) influenced by peripheral nerve activity and descending brain pathways before reaching the brain.
Key Term: Modulation (Pain Process)
The effect of interneurons on afferent pain neurons in the spinal cord; can amplify or dampen pain signals. Influenced by ascending/descending nerve tracts.
Key Term: Neuromatrix Theory
Theory that pain is a multidimensional experience generated by a “body-self neuromatrix” in the brain, influenced by sensory input, genetics, and life experiences. Pain can be generated by brain independently.
