1、Pain Modulaton,Stopping the Hurt,Pain Modulaton,Stopping the Hurt,The Problem with Pain, 2 Million workers incapacitated by pain all the time. $2.5 billion Sensation with Authority Sensation versus Perception Pain Sensation versus Pain Perception The Mighty Placebo,Why does aspirin help alleviate pa
2、in?,All Mighty Aspirin,Chemoreceptors and Prostaglandin Sensitization of Receptors Prostaglandin Synthesis Blocked by Aspirin Anti-Inflamatory Drugs Pain and the Immune System,If you hurt yourself, you often rub the affected area to make it feel better. Why does this work?,Counter Irritant Theory,Ga
3、te Control Theory Gate Cells Tract Cells Touch Input Ab Fibers Local Inhibition GABA and Enkephalin TENS, and other Rx,Opium, an extract of a poppy plant, has very powerful analgesic properties. It does this because the neurons in the pain system have receptors that bind opiods. Why would the nervou
4、s system develop neurotransmitter receptors to a poppy plant?,Searching for Endogenous Opium,Opiods (Opium, Heroin, etc) are analgesics Opiods act on neuron chemoreceptors Does the CNS makes Opiods? Yes! Proteins - b-Endorphin Peptides - Enkephalin, Dynorphin One site of action Dorsal Horn Gate Cell
5、s,Descending Pain Control,Periaqueductal Gray Opiod Receptors Projects to Raphe Nuclei Raphe Nuclei Project down to dorsal horn and Spinal 5 Nucleus Serotonin (5-HT) Inhibits Ascending Systems Blocks Substance P release by Primary Afferents Locus Coeruleus Descending Norepinephrine Activates Enkepha
6、lin Interneurons Hormonal Analgesia Beta Endorphin,The Mighty Placebo,What is referred pain? What is the current explanation of this phenomena?,Localization of Visceral Pain,Visceral Pain Nociceptors in the Viscera Not Localizable Convergence on ALF Tract Cell Mislocalization in cord,What are severa
7、l different types of chronic pain and how do they differ in terms of etiology?,Good Pain and Bad Pain,Good Pain - It Hurts, but Helps Acute Pain, Hurts until the problem is solved Bad Pain - It Hurts for no good reason Chronic Pain, Pain Persists after healing,Types of Chronic Pain,Nociceptive Chron
8、ic Pain SemiGood Pain Cancer, Arthritis, Nerve Compression Neuropathic Chronic Pain Peripheral Mechanisms CNS Mechanisms Sympathetic Maintained Pain,Peripheral Chronic Pain,Neuroma Ectopic Foci Receptor Changes Immune Responses Maybe not all peripheral,CNS and Neuropathic Pain,Spinal Plasticity Synapses and Receptors Cortical Plasticity Changes in the Homunculus,Sympathetically Maintained Pain,Syndrome Minor Trauma, Limb Immobility Poor Healing and Red, Sweating Skin Extreme Pain Early on and gets worse Rx Block (cut) the Sympathetic Ganglia Etiology Unknown Theories,
