Med Phys Pharm 551 L22 ANS Phys 10-30-24 PDF
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Uploaded by .keeks.
Marian University
Julia Hum, PhD
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Summary
This document is a lecture on autonomic nervous system (ANS) physiology for medical students. It covers learning objectives, different components, mechanisms, and the organization of the ANS. The document includes a summary of the key takeaways and explanations for each topic covered.
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Lecture #22: ANS Physiology Julia Hum, PhD Primary Course Instructor Course Meets: Monday/Wednesday/Friday: 2:00-2:50pm Office Hours: Monday/Wednesday/Friday 11:00am-12:00pm (317B or WebEx) L22: Learning Objectives 1. Describe th...
Lecture #22: ANS Physiology Julia Hum, PhD Primary Course Instructor Course Meets: Monday/Wednesday/Friday: 2:00-2:50pm Office Hours: Monday/Wednesday/Friday 11:00am-12:00pm (317B or WebEx) L22: Learning Objectives 1. Describe the organization of the ANS 2. Know the main function of the ANS and how its carried out 3. Characterize the synapse pathway for the sympathetic and parasympathetic pathways and their effector organs 4. Compare and contrast the autonomic and motor systems 5. Describe the organization of the sympathetic division of the ANS 6. Differentiate between neurotransmission of the somatic nervous system, sympathetic nervous system and the parasympathetic nervous system 7. Diagram the autonomic control centers 8. Describe the organization of the brainstem and its control centers Take Home: Nervous System NT Roadmap CNS ANS LO1 Overview and Introduction Overview Homeostasis ANS Organization Neurotransmision ANS Effector Organs Roles of: Brainstem Hypothalamus Limbic System https ://cl assc onne ction.s3.a ma zonaws.c om/420/flashc ards/1094420/jpg/ne rvous_s yste m_ org aniza tion1328056081853. jpg LO1 Autonomic Control Centers LO7 Main Function of ANS: Maintain Homeostasis How? Needed at both the cellular and organismal level Usually a negative feedback loop 1. Sensory component 2. Integrator 3. Effector component Mechanisms Redundancy LO2 Functional Reserve Main Function of ANS: Maintain Homeostasis Mechanisms: Homeostatic control pathways Present at the cellular and organismal level 1. Negative feedback control system 2. Sensory component 3. Integrator LO2 Main Function of ANS: Maintain Homeostasis Redundancy Important to involve multiple control pathways Layered and usually hierarchical # layers reflects importance Blood Pressure – Cardiovascular Control Center Adjust vascular tone and cardio output Ensures if one control pathway fails other redundant pathways will continue homeostasis https ://dr282zn36sx xg. cloudfront.ne t/ data strea ms/f-d%3A c04636fae 272893b86fe 2113b800b0cf772dc 17e 8544f521d4ab970b%2BIM AGE _ TI NY %2BI MAG E_ T INY.1 LO2 Main Function of ANS: Maintain Homeostasis Functional Reserve Important for organs charged with maintaining homeostasis Examples: 1. Lung capacity – at rest use ~10% capacity 2. Cardiac output – at rest use ~20% max output ht tp:/ /www.nuffieldf oundatio n.org/ sites /d efault/ files/ PB_us ing-a-s piromet er-to-inves tigate-hum an-lung-fun ct ion-20-s tandard-curve-s howing-vital-capacit y-500.jpg Pitfall of functional reserve comes with aging and disease LO2 ANS Organization LO1 The Sympathetic and Parasympathetic Pathways Innervate by a Two-Synapse Pathway 1st Cell Body 2nd Cell Body Boron and Boulpaep: Medical Physiology , 3ed Sympathetic and Parasympathetic can work independently, but usually work together LO3 Comparing the Autonomic and Somatic Motor Systems http://ant ranik.org/wp-content/uploads/2011/11/compari son-of-aut onomic-and-somatic-motor-systems-cell-bodies-axons-effect-neurotransmittor-ach-ne.jpg LO4 Organization of the ANS Divisions Cell body location Preganglionic/Postganglionic length LO5 Boron and Boulpaep: Medical Physiology , 3ed Nicotinic Receptors Ionotropic Receptors Na+ influx and membrane depolarization Neuromuscular Junction ANS Neurotransmission GPCR Adrenergic or Muscarinic Receptors LO6 Muscarinic vs Nicotinic Receptors Nicotinic Receptors Ionotropic Depolarization https ://qph.e c.quoracdn.ne t/ma in-qimg -380298715a 12e 9c 4f29a f7919b039fb5? conve rt_ to_we bp= true LO6 Muscarinic vs Nicotinic Receptors GPCR – slow and prolonged response 1. Stimulate hydrolysis of IP3, increase Ca++, activate PKC 2. Inhibit AC, decrease cAMP 3. Directly modulate K+ through beta/gamma subunit LO6 https://humanphysiology2011.wikispaces.com/file/view/Muscarinic_ACh_receptors.jpg /217816326/433x385/Muscarinic_ACh_receptors.jpg Adrenergic Receptors NE LO6 https ://upload.wik ime dia.org/wik ipedia /comm ons/f/f7/A dre noce ptor-S igna l_tra ns duk tion. PNG Postganglionic Synapses Each varicosities is a site of: Transmitter synthesis Storage Release Functions as the site of a nerve terminal LO6 http://classes.midlandstech.edu/carterp/Courses/bi o210/chap09/210_figure_09_26_labeled.jpg Effector Organs LO3 Brainstem is the Primary Controller of the ANS Home to the Parasympathetic preganglionic nuclei Edinger-Westphal nucleus Superior and Inferior salivary nuclei Dorsal motor nucleus of vagus Nucleus ambiguus LO10 Brainstem Control Centers 1. Respiratory Center Chemoreceptors monitor arterial O2, CO2, pH Controls respiration rate 2. Cardiovascular Center Baroreceptors and chemoreceptors Controls blood pressure through modulation of cardiac output and vascular tone 3. Micturition Center Urinary bladder distension LO10 Nucleus Tractus Solitarius (NTS) Considered one of the most important lower brainstem structures Runs the length of the medulla Coordinates autonomic functions and reflexes Input: Receives data from visceral regions via vagus and glossopharyngeal nerves Output: Relays back to hypothalamus LO8 Autonomic Control Centers LO7
