The Nature & Symptoms of Pain Chapter 11

Qualities & Dimensions of Pain Organic pain vs. Psychogenic pain Acute vs. Chronic Pain

Qualities & Dimensions of Pain Chronic pain – Benign vs. Malignant – Continuous vs. Episodic – Types Chronic/recurrent Chronic/intractable/benign Chronic/progressive

Assessing Pain Self-Report Methods Questionnaires Behavioral Assessment Physiological Measures

Personal & Social Experiences and Pain Learning Emotions

Physiology of Pain Perception Noxious stimulation release of algogenic substances at the site – e.g., serotonin, histamine, bradykinin Algogenic substances promote immune system activity (inflammation) Inflammation activates free nerve endings signaling pain – Free nerve endings: nociceptors

Physiology of Pain Perception Afferent peripheral fibers – A-delta fibers – C fibers

Pain Without Apparent Physical Basis Types – Neuralgia – Causalgia – Phantom Limb Pain

Theories of Pain Specificity Theory Pattern Theory Gate Control Theory

Transmission cells (T cells) Brain Substantia Gelatinosa “The Gate” Small A-delta & C fibers Large A-beta fibers

Theories of Pain Interneurons Basbaum & Field’s Descending Analgesic Pathway Periaqueductal Grey Grey Incoming Pain Signals Spinal Cord Raphe Nucleus Ascending Anterolateral Pathway to brain + - Opiates inhibit inhibitory neurons of PAG disinhibition