This document discusses pain physiology and provides definitions and classifications of pain. It describes the types of pain fibers and the pain pathway in the spinal cord. It also summarizes nociception, the modulation of pain both peripherally and centrally, and the differences between acute and chronic pain. Finally, it outlines some of the physiological effects pain can have on various body systems.

1. PAIN PHYSIOLOGY BY Dr. Vemanna Naik

3. VARIOUS TERMINOLOGIES FUNCTIONAL ABNORMALITY OF NERVE ROOTS RADICULOPATHY ABNORMAL SENSATION PERCEIVED WITHOUT AN APPARENT STIMULUS PARASTHESIA PAIN IN THE DISTRIBUTION OF A NERVE NEURALGIA REDUCED CUTANEOUS SENSATION HYPOASTHESIA INCREASED RESPONSE TO MILD STIMULUS HYPERASTHESIA INCREASED RESPONSE TO NOXIOUS STIMULUS HYPERALGESIA DIMINISHED RESPONSE TO NOXIOUS STIMULUS HYPOALGESIA UNPLEASANT SENSATION WITH OR WITHOUT STIMULUS DYSESTHESIA PAIN IN AN AREA THAT LACKS SENSATION ANESTHESIA DOLOROSA ABSENCE OF ALL SENSATIONS ANESTHESIA ABSENCE OF PAIN PERCEPTION ANALGESIA PERCEPTION OF NON-NOXIOUS STIMULUS AS PAIN ALLODYNIA DESCRIPTION TERM

5. TYPES OF PAIN FIBRES DULL ACHE, DIFFUSE No 1 (slow) C SHARP, PRICKING,WELL LOCALIZED YES 20 (fast) A- DELTA TYPE OF PAIN MELINATED CONDUCTION VELOCITY ( MTS/SEC ) TYPE OF NERVE

6. PAIN PATHWAY

7. SPINALCORD LAMINAE CENTRAL CANAL Aβ X MOTOR HORN Aβ MOTOR IX MOTOR HORN Aβ VIII INTERMEDIOLATERAL COLUMNS SYMPATHETIC VII NUCLEUS PROPRIUS Aβ MECHANORECEPTION VI NUCLEUS PROPRIUS WDR NEURONS Aβ, Aδ, C VISCERAL & SOMATIC NOCICEPTION & MECHANORECEPTION V NUCLEUS PROPRIUS Aβ, Aδ, MECHANORECEPTION IV NUCLEUS PROPRIUS Aβ, Aδ SOMATIC NOCICEPTION MECHANORECEPTION III SUBSTANTIA GELATINOSA C, Aδ SOMATIC NOCICEPTION THERMORECEPTION II MARGINAL LAYER Aδ, C SOMATIC NOCICEPTION THERMORECEPTION I NAME INPUT PREDOMINANT FUNCTION LAMINA

10. CHEMICAL MEDIATORS INHIBITORY GLYCINE INHIBITORY A.B GABA INHIBITORY 5-HT SEROTONIN INHIBITORY A1 ADENOSINE INHIBITORY Α2 NOREPINEPHRINE INHIBITORY µ, δ, κ B- ENDORPHIN INHIBITORY µ, δ, κ ENKEPHALIN INHIBITORY M1 Ach INHIBITORY SOMATOATATIN EXCITATORY P1, P2 ATP EXCITATORY NMDA ASPARTATE EXCITATORY NMDA GLUTAMATE EXCITATORY CALCITONIN EXCITATORY NK – 1 SUBTANCE P EFFECT ON NOCICEPTION RECEPTOR NEUROTRANSMITTER

17. REFERRED PAIN

18. PHYSIOLOGICAL EFFECTS OF PAIN Hyperglycemia Sodium & water retention Protein catabolism Endocrine system HTN Tachycardia Myocardial Ischemia Cardiac Dysrhythmia CVS(SNS Stim) Atelectasis Ventilation perfusion mismatch Arterial hypoxemia Hypercarbia pneumonia Pulmonary (Dec lung volume)

19. PHYSIOLOGICAL EFFECTS OF PAIN Urinary retention Genitourinary system Ileus GI system Increased platelet adhesiveness Decreased fibrinolysis Hypercoagulation DVT Coagulation system Decreased immune function Immune system

20. THANK YOU