Autonomic nervous system

Autonomic Nervous System

1. AUTONOMIC NERVOUS SYSTEM Presented By: Dr. SAPNA VADERA Dept. of OMFS, VSPM’s DCRC, Nagpur Guided By : Dr. S.R.SHENOI Prof. And Head, Dept. Of OMFS, VSPM’s DCRC, Nagpur

2. Contents… Introduction Comparison b/w somatic and autonomic nervous system Divisions of ANS Comparison b/w sympathetic and parasympathetic nervous system Autonomic tone

3. Contents… Ganglions Sympathetic nervous system Parasympathetic nervous system Dual innervations Neurotransmitters Pharmacology Applied aspects Conclusion References

4. Contents… Introduction …

5. Comparison …

6. Comparison … Guyton and Hall , Textbook Of Medical Physiology, 11 th edition; 2006; Elsevier Inc.1600 John F. Kennedy Blvd., Suite 1800 Philadelphia.

7. AUTONOMIC NERVOUS SYSTEM

8. Striking characteristics of the ANS The rapidity and intensity. Within 3 to 5 seconds- increases heart rate to twice normal. Within 10 to 15 seconds the arterial pressure doubled. The arterial pressure can be decreased low enough within 10 to 15 seconds to cause fainting. Sweating can begin within seconds, and the urinary bladder may empty involuntarily , within seconds. Guyton and Hall , Textbook Of Medical Physiology, 11 th edition; 2006; Elsevier Inc.1600 John F. Kennedy Blvd., Suite 1800 Philadelphia.

9. Central Control of ANS Cerebral cortex through the hypothalamus and reticular formation Brain stem - reflexes for heart rate and BP Spinal cord - reflexes for urination, defecation and erection Taylor EW, Jordan D, Coote JH: Central control of the cardiovascular and respiratory systems and their interactions in vertebrates. Physiol Rev 79:855, 1999.

10. Autonomic Visceral Reflex Arc Taylor EW, Jordan D, Coote JH: Central control of the cardiovascular and respiratory systems and their interactions in vertebrates. Physiol Rev 79:855, 1999.

11. Two divisions: Sympathetic and Parasympathetic Usually two systems work together to maintain a balanced state or homeostasis in the body Comparison … Guyton and Hall , Textbook Of Medical Physiology, 11 th edition; 2006; Elsevier Inc.1600 John F. Kennedy Blvd., Suite 1800 Philadelphia.

12. Sympathetic and Parasympathetic ‘tone’

13. SYMPATHETIC NERVOUS SYSTEM Acts in times of emergency such as ‘FRIGHT’ or ‘FLIGHT’ Prepares the body to act Increases heart rate and respiration Raises blood pressure Slows activity in the digestive tract Guyton and Hall , Textbook Of Medical Physiology, 11 th edition; 2006; Elsevier Inc.1600 John F. Kennedy Blvd., Suite 1800 Philadelphia.

14. PARASYMPATHETIC NERVOUS SYSTEM Counteracts the actions of the sympathetic after the emergency Dominates in quite and relaxed conditions ‘House keeping functions’ – digestion and micturition Slows the heart rate and respiration Lowers the blood pressure

15. Two Cell Motor Pathway The first is the preganglionic neuron, whose cell body is located in the brain or spinal cord In the sympathetic division, the cell body is located in the lateral grey horns ( thoraco -lumbar) In the parasympathetic division, the cell body is located in various nuclei of brain stem or in the lateral grey horns (sacral ) Guyton and Hall , Textbook Of Medical Physiology, 11 th edition; 2006; Elsevier Inc.1600 John F. Kennedy Blvd., Suite 1800 Philadelphia.

16. Two Cell Motor Pathway The second is the postganglionic neuron, whose cell body is in an autonomic ganglion - The postganglionic fiber sends impulses to a target organ - The effects at the target organ are due to type of neurotransmitter and specific cell surface receptors on the effector cells Guyton and Hall , Textbook Of Medical Physiology, 11 th edition; 2006; Elsevier Inc.1600 John F. Kennedy Blvd., Suite 1800 Philadelphia.

17. Two Cell Motor Pathway Guyton and Hall , Textbook Of Medical Physiology, 11 th edition; 2006; Elsevier Inc.1600 John F. Kennedy Blvd., Suite 1800 Philadelphia.

18. SYMPATHETIC PARASYMPATHETIC PREGANGLIONIC FIBRES THORACOLUMBAR DIVISION CRANIOSACRAL DIVISION LENGTH OF PREGANGLIONIC AXONS SHORT LONG PREGANGLIONIC FIBRES TRAVEL IN VENTRAL ROOT OF A SPINAL NERVE CRANIAL NERVE OR VENTRAL ROOT OF A SPINAL NERVE GANGLION PARAVERTEBRAL GANGLION AND PREVERTEBRAL GANGLION TERMINAL GANGLION THE PREGANGLIONIC AXON SYNAPSES WITH: A LARGE NUMBER OF POSTGANGLIONIC NEURONS A SMALL NUMBER OF POSTGANGLIONIC NEURONS EFFECTS WIDESPREAD NARROW LENGTH OF POSTGANGLIONIC AXONS LONG SHORT GENERAL DESCRIPTION OF EFFECTS "FIGHT-OR FLIGHT" RESPONSE "HOUSEKEEPING" MOST BODY STRUCTURES RECEIVE DUAL INNERVATION, BUT A FEW ARE INNERVATED BY ONE DIVISION ONLY SWEAT GLANDS, ARRECTOR PILI MUSCLES, FAT CELLS, CUTANEOUS BLOOD VESSELS LACRIMAL (TEAR) GLANDS

19. SYMPATHETIC NERVOUS SYSTEM

20. PARASYMPATHETIC NERVOUS SYSTEM

21. The Autonomic Nervous System Structure Sympathetic Stimulation Parasympathetic Stimulation Iris (eye muscle) Pupil dilation Pupil constriction Salivary Glands Saliva production reduced Saliva production increased Oral/Nasal Mucosa Mucus production reduced Mucus production increased Heart Heart rate and force increased Heart rate and force decreased Lung Bronchial muscle relaxed Bronchial muscle contracted Stomach Peristalsis reduced Gastric juice secreted; motility increased Small Intestine Motility reduced Digestion increased

22. Large Intestine Motility reduced Secretions and motility increased Liver Increased conversion of glycogen to glucose Kidney Decreased urine secretion Increased urine secretion Adrenal medulla Norepinephrine and epinephrine secreted Bladder Wall relaxed Sphincter closed Wall contracted Sphincter relaxed Structure Sympathetic Stimulation Parasympathetic Stimulation Guyton and Hall , Textbook Of Medical Physiology, 11 th edition; 2006; Elsevier Inc.1600 John F. Kennedy Blvd., Suite 1800 Philadelphia.

23. Sympathetic Division ‘ Thoracolumbar ’

24. The Sympathetic Division Guyton and Hall , Textbook Of Medical Physiology, 11 th edition; 2006; Elsevier Inc.1600 John F. Kennedy Blvd., Suite 1800 Philadelphia.

25. The Sympathetic Ganglion Paravertebral ganglion Located parallel to spinal cord on either side Connected to the spinal nerve through the grey and white rami Prevertebral Gangliaon Lie anterior to the vertebral column Occur only in abdomen and pelvis Unpaired, not segmentally arranged Also called collateral Guyton and Hall , Textbook Of Medical Physiology, 11 th edition; 2006; Elsevier Inc.1600 John F. Kennedy Blvd., Suite 1800 Philadelphia.

26. Postganglionic Neurons 3 types of postganglionic fibres Which enter the spinal nerve through the grey ramus Which travel along the blood vessels to supply head & neck From collateral ganglia which travel short distance to innervate visceral organs Guyton and Hall , Textbook Of Medical Physiology, 11 th edition; 2006; Elsevier Inc.1600 John F. Kennedy Blvd., Suite 1800 Philadelphia.

27. The Sympathetic Ganglion

28. Sympathetic Pathways to the Head Figure 15.10

29. Sympathetic Pathways to Thoracic Organs Figure 15.11

30. Sympathetic Pathways to Periphery Figure 15.9

31. The Adrenal Medulla Figure 15.14

32. Parasympathetic Division ‘ Craniosacral ’

33. The Parasympathetic Division Preganglionic neurons originate in the brainstem and the lateral horn of the spinal cord in sacral region Pass through cranial nerves III, VII, IX, X and S 2-4 Extend some distance, synapse in terminal ganglia , and release Ach Guyton and Hall , Textbook Of Medical Physiology, 11 th edition; 2006; Elsevier Inc.1600 John F. Kennedy Blvd., Suite 1800 Philadelphia.

34. Postganglionic neurons originate in the terminal ganglia, pass a short distance and then release Ach

35. Parasympathetic innervations

36. Cranial Outflow Nerve Origin of preganglionic fibers Location of terminal ganglia Effector organ Occulomotor nerve (III) nerve Midbrain Cilliary ganglion Eyes (smooth muscle in iris & cilliary body ) Facial (VII) nerve Pons Pterygopalatine & submandibular ganglia Lacrimal , Salivary & mucous glands Glossopharyngeal (IX) nerve Medulla oblongata Otic ganglion Parotid gland Vagus (X) nerve Medulla oblongata Terminal ganglia Heart, lungs, GI tract, liver, pancreas

37. Sacral Outflow Emerges from S 2 -S 4 Form splanchnic nerves Innervates lower half of large intestine, rectum, urinary bladder, reproductive organs Guyton and Hall , Textbook Of Medical Physiology, 11 th edition; 2006; Elsevier Inc.1600 John F. Kennedy Blvd., Suite 1800 Philadelphia.

38. ANS Dual Innervations The Sympathetic and Parasympathetic -- Divisions of the ANS innervate many of the same organs -Different effects are due to specific different neurotransmitters and receptor types of effectors Guyton and Hall , Textbook Of Medical Physiology, 11 th edition; 2006; Elsevier Inc.1600 John F. Kennedy Blvd., Suite 1800 Philadelphia.

39. ANS Dual Innervations

40. Neural Communication Neurotransmitters C hemical messengers that traverse the synaptic gaps between neurons W hen released by the sending neuron, neurotransmitters travel across the synapse and bind to receptor sites on the receiving neuron, and thereby bring about effect K D Tripathi , Essentials of Medical Pharmacology,6 th edition,2008 Jaypee brothers medical publishers,Delhi

41. Neurotransmitters ACh ACh Sweat glands Striated muscle ACh SOMATIC NERVOUS SYSTEM Heart Sm. mus. Glands ACh ACh Parasympathetic ACh E, NE Ad. M.   Heart Sm. mus. Glands ACh NE AUTONOMIC NERVOUS SYSTEM Sympathetic

42. Neurotransmitters Guyton and Hall , Textbook Of Medical Physiology, 11 th edition; 2006; Elsevier Inc.1600 John F. Kennedy Blvd., Suite 1800 Philadelphia.

43. Adrenergic receptors α 1 - smooth muscles, blood vessels, glands & gut α 2 - nerve endings, β cells β 1 - heart, JG cells β 2 - bronchi, blood vessels, liver K D Tripathi , Essentials of Medical Pharmacology,6 th edition,2008 Jaypee brothers medical publishers,Delhi

44. NEpi α 1 Epi β 1 β 2 Generally excitatory effect on cell, except at GI smooth muscle Excitatory effect on cardiac muscle cells Generally very powerful inhibitory effect on cell K D Tripathi , Essentials of Medical Pharmacology,6 th edition,2008 Jaypee brothers medical publishers,Delhi

45. Cholinergic receptors Muscarinic – heart, blood vessels, eye, smooth muscles, GI glands Nicotinic – skeletal muscles, end plate of ganglionic cells K D Tripathi , Essentials of Medical Pharmacology,6 th edition,2008 Jaypee brothers medical publishers,Delhi

46. Pharmacology Neurotransmitters of the Autonomic Nervous System

47. Adrenergic agents/ ,44 Adrenaline Anaphylaxis Physiologic antagonist of histamine Reverse vasodilatation & bronchospasm brought about by histamine Act on β 2 & α 1 receptors Hypotension Bronchial asthma Act on β 2 receptor & cause bronchodilatation Cardiac arrest Act on β 1 receptor to stimulate heart K D Tripathi , Essentials of Medical Pharmacology,6 th edition,2008 Jaypee brothers medical publishers,Delhi

48. Dopamine Useful in cardiogenic shock to ↑ supply to renal tissues as D 1 receptors in renal and mesentric blood vessels are most sensitive Increases g.f.r Used in patients with cardiogenic /septic shock and severe CHF- increases B.P and urinary blood flow Adrenergic agents/ Sympathomimetics K D Tripathi , Essentials of Medical Pharmacology,6 th edition,2008 Jaypee brothers medical publishers,Delhi

49. Adrenergic antagonists/ Sympatholytics α blockers Prazosine - in hypertension β blockers Atenolol - its cardioselective β blocker Hypertension, Angina pectoris, MI, arrhythmia K D Tripathi , Essentials of Medical Pharmacology,6 th edition,2008 Jaypee brothers medical publishers,Delhi

50. Cholinergic drugs/ Parasympathomimetics Pilocarpine Mainly muscarinic actions ↑ secretions, salivation, miosis Anticholinesterase Neostigmine Mainly nicotinic action Reverses muscle paralysis after anesthesia Post op paralytic ileus / urinary retention In snake bite along with atropine to prevent respiratory paralysis K D Tripathi , Essentials of Medical Pharmacology,6 th edition,2008 Jaypee brothers medical publishers,Delhi

51. Anticholinergic drugs/ Parasympatholytics Atropine Blocks mainly muscarinic actions Preanesthetic medication ↓ secretions Muscle relaxant Cardiac vagolytic Helps in counteracting bradycadia and partial heart block→ ↑heart rate K D Tripathi , Essentials of Medical Pharmacology,6 th edition,2008 Jaypee brothers medical publishers,Delhi

52. Applied Aspects

53. Horner’s syndrome Ptosis Miosis Anhydrosis Maloney WF, Younge BR, Moyer N. Evaluation of the causes and accuracy of pharmacologic localization in Horner syndrome. Am J Ophthalmol 1980;90:394-402.

54. Frey Syndrome Auriculotemporal syndrome or gustatory sweating and flushing results from nerve injury, usually post-surgical or post-infection. This nerve carries parasympathetic fibers to the parotid and sympathetic vasomotor fibers to the preauricular skin. 5% resolve; if needed, possible treatment ranges from atropine or botox injections, scopolamine cream or severing the nerve. Linder TE, Huber A, Schmid S. Frey’s syndrome after parotidectomy:a retrospective and prospective analysis. Laryngoscope1997;107(11):1496-501.

55. Frey Syndrome Linder TE, Huber A, Schmid S. Frey’s syndrome after parotidectomy:a retrospective and prospective analysis. Laryngoscope1997;107(11):1496-501.

56. Myasthenia Gravis 1 in 10,000 population . Antibodies directed against nicotinic receptors. Weakness and easy fatigability on repeated activity, with recovery after rest. Neostigmine 15mg QID . Pridnisolone 30-60mg/day. (inhibits production of antibodies) K D Tripathi , Essentials of Medical Pharmacology,6 th edition,2008 Jaypee brothers medical publishers,Delhi

57. Raynaud’s Disease S evere vasoconstriction of the blood supply to the fingers, toes and occasionally the ears and nose During a Raynaud’s attack, skin color changes (pallor, cyanosis, rubor ) which are often accompanied by a throbbing or burning sensation, cold, and numbness occur I schemia can be so extreme as to cause gangrene Landry GJ:Current medical and surgical management of Raynaud’s syndrome. JVascSurg57:1710-1716,2013

58. SHOCK COMPENSATORY MECHANISM Sympathetic Nervous System (SNS)-Adrenal Response SNS - Neurohormonal response Stimulated by baroreceptors Increased heart rate Increased contractility Increased Preload Vasoconstriction Guyton and Hall , Textbook Of Medical Physiology, 11 th edition; 2006; Elsevier Inc.1600 John F. Kennedy Blvd., Suite 1800 Philadelphia.

59. SNS - Renin-angiotensin system Decrease renal perfusion Releases renin angiotensin I angiotensin II ( (potent vasoconstriction) releases aldosterone adrenal cortex sodium & water retention increased blood volume and pressure Guyton and Hall , Textbook Of Medical Physiology, 11 th edition; 2006; Elsevier Inc.1600 John F. Kennedy Blvd., Suite 1800 Philadelphia.

60. SNS - Hormonal: Antidiuretic Hormone Osmoreceptors in hypothalamus stimulated ADH released by Posterior pituitary gland Vasopressor effect to increase BP Acts on renal tubules to retain water Guyton and Hall , Textbook Of Medical Physiology, 11 th edition; 2006; Elsevier Inc.1600 John F. Kennedy Blvd., Suite 1800 Philadelphia.

61. Referred pain Referred pain is a phenomenon in which pain originating in one part of the body is felt as though it originated in another part of the body . Guyton and Hall , Textbook Of Medical Physiology, 11 th edition; 2006; Elsevier Inc.1600 John F. Kennedy Blvd., Suite 1800 Philadelphia. Eg . afferents from the heart enter the spinal cord at the same level as those from the shoulder region. This is why pain in the heart (a heart attack) is often referred to the shoulder. The sympathetic afferents mainly carry information about visceral pain. Since this information converges with pain from the body surface, the pain is often perceived as originating at the body surface instead of deep in the viscera.

62. Role of ANS in Post-surgical Patients Post – operative arrythmia and hypertension Operative stress causes sympathetic overactivity which stimulates the heart to maintain high rate and pressure Post – operative urine retention It is normal for a patient to have reduced urine output for 24 hrs post – operatively due to the overactive sympathetic system. Care should be taken if this extends for a longer period Guyton and Hall , Textbook Of Medical Physiology, 11 th edition; 2006; Elsevier Inc.1600 John F. Kennedy Blvd., Suite 1800 Philadelphia.

63. Use of ANS in lie detector Lie detectors work by recording changes in heart rate, or in the sweatiness of palms - both of these increase when someone is telling a lie

64. Studying ANS helps to understand the body responses to stressful conditions like trauma, infection and surgery. Conclusion Further research about the receptors, neurotransmitters and the agents acting on them can aid in better control over the various body responses in stress and at rest. Closely monitored medication can be use to control the neurotransmitters to alleviate symptoms that may be associated with diseases. Guyton and Hall , Textbook Of Medical Physiology, 11 th edition; 2006; Elsevier Inc.1600 John F. Kennedy Blvd., Suite 1800 Philadelphia.

65. K D Tripathi , Essentials of Medical Pharmacology,6 th edition,2008 Jaypee brothers medical publishers,Delhi Taylor EW, Jordan D, Coote JH: Central control of the cardiovascular and respiratory systems and their interactions in vertebrates. Physiol Rev 79:855, 1999. Guyton and Hall , Textbook Of Medical Physiology, 11 th edition; 2006; Elsevier Inc.1600 John F. Kennedy Blvd., Suite 1800 Philadelphia. Maloney WF, Younge BR, Moyer N. Evaluation of the causes and accuracy of pharmacologic localization in Horner syndrome. Am J Ophthalmol 1980;90:394-402. Linder TE, Huber A, Schmid S. Frey’s syndrome after parotidectomy : a retrospective and prospective analysis. Laryngoscope1997;107(11):1496-501. 6. Landry GJ:Current medical and surgical management of Raynaud’s syndrome. JVascSurg57:1710-1716,2013 References

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