Autonomic Nervous System: Organization, Neurotransmitters, and Receptors, Study Guides, Projects, Research of Anatomy

Download Autonomic Nervous System: Organization, Neurotransmitters, and Receptors and more Study Guides, Projects, Research Anatomy in PDF only on Docsity! LECTURE 9 and 10 • Red : important • Black : in male / female slides • Pink : in girls slides only • Blue : in male slides only • Green : notes, Extra AUTONOMIC NERVOUS SYSTEM (l) & (ll) Version 2 Objectives • At the end of this lecture, students should be able to: 1. Appreciate the anatomy of the Sympathetic & Parasympathetic nervous system 2. Explain Physiological functions of Sympathetic & Parasympathetic nerves in the head, neck, chest, abdomen, and pelvis. 3. Organization of the Autonomic Nervous system 4. Neurotransmitters and Receptors 5. Agonists and Antagonists to Autonomic receptors 6. Sympathetic & Parasympathetic Tone 7. Examples Autonomic nervous system (ANS) • Organization of autonomic nervous system motor pathway consists of two neurons: - Preganglionic neuron. (cell body inside CNS “in brain or cord”) - Postganglionic neuron. (cell body in ganglion outside CNS) vAll preganglionic neurons release Acetylcholine (Ach). vPostganglionic release either Ach or norepinephrine. Organization of the Autonomic Nervous System This picture was only found in male slides Autonomic nervous system • ANS: is the subdivision of the peripheral nervous system that regulates body activities that are generally not under conscious control. • Visceral motor innervates non-skeletal (non-somatic) muscles. Composed of a special group of neurons serving Cardiac muscle (the heart) Smooth muscle (walls of viscera and blood vessels) Internal organs Skin Found in girls slides only Terminology SYMPATHETIC AND PARASYMPATHETIC ADRENERGIC AND CHOLINERGIC anatomic terms and refer to anatomic origin of preganglionic neurons in the central nervous system. terms are used to describe neurons of either division, according to which neurotransmitter they synthesize and release. v Adrenergic neurons release nor-epinephrine and the receptor is adrenoreceptor v Cholinergic neurons release Ach and the receptor is cholinergic Higher control of the autonomic Nervous System • - Sympathetic NS is regulated by neurons in the Posterior part of the hypothalamus. • - Parasympathetic NS is regulated by neurons in the Anterior part of the hypothalamus. This part was only found in girls slides This part was only found in male slides The autonomic nervous system Subdivision Nerves Employed Location of Ganglia Chemical Messenger General Function Sympathetic Thoracolumbar Alongside vertebral column Norepinephrine Fight or flight Parasympathetic Craniosacral On or near an effector organ Acetylcholine Conservation of body energy Girls slides رصتخی دیالسلا اذھ لبق يللا نیدیالسلا SYMPATHETIC & PARASYMPATHETIC NERVOUS SYSTEM ORIGIN • Blue= Para symp; Red symp ANS NEUROTRANSMITTERS • ANS Neurotransmitters: Classified as either cholinergic or adrenergic neurons based upon the neurotransmitter released. Norepinephrine Acetyl choline Sympathetic Neurotransmitters Note: they’re named after drugs they’re sensitive to * Remmber: ANS motor pathway consists of two neurons: • Preganglionic neuron : inside CNS ( in brain or spinal cord ) • Postganglionic neuron : outside CNS (cell body in ganglion outside CNS) (Acetylcholine) Parasympathetic Neurotransmitters • Pre & Postganglionic neurons release: • acetylcholine = Cholinergic Autonomic nervous system: (neurotransmitters) preganglionic postganglionic parasympathetic acetyl choline acetyl choline sympathetic acetyl choline norepinephrine* Adrenal medulla: preganglionic - acetyl choline postganglionic (chromaffin cell) - 80% epinephrine, 20% norepinephrine Found in girls slides only Sympathetic vs. Parasympathetic Receptors In sympathetic nervous system • Pre receptor: Nicotinic • Post receptor: Adrenoreceptor (α and β) except in sweat glands where it is Muscarinic In parasympathetic nervous system • Pre receptor: Nicotinic • Post receptor: Muscarinic (Because the ONLY neurotransmitter in parasympathetic: acetylcholine (Ach) All preganglionic autonomic receptors are nicotinic Sympathetic Adrenergic Receptors Parasympathetic muscarinic receptors Chemical or neural transmitter All preganglionic fibers release acetylcholin (Ach). All parasympathetic postganglionic release Ach. All sympathetic postganglionic release noradrenalin except sweat glands & blood vessels to skeletal muscles. Found in girls slides only a1 receptor β1, β2 receptors Found in males slides only Cholinorecepters Found in males slides only All the green texts are notes or extra information كسمی نیلوك لیاتیسالا يجی امل integral protein( نیتوربلاب مویدوصلا يلخیو جشابلا كفی ( يز اوكرحتی مویساتوبلاو downhillىلع علطی مویساتبلا ،اوج ىلع علطی مویدوصلاو ارب سب فتیقن نوكی ةیلخلا اوج ةداع مویدوص لخدیب لیناشتلا حتفنی امل حارف مویساتوب علطی امم رثكا اذھ فتیزوب اوج نم ةیلخلا نوكت فتیزوبلل فتیقانلا نم تفشلا وھو depolarization ھیمسن ھیلخ نم لینقسلا كرحی يللا ھسفن نوروینلاب ریصی يللا وھ ةیلخل ....تالضعلاو ھنم ىوقا ھنا سبrepolarization ھسفن ھعجری حار سكعلا فیتقینل فتیزوب نم nicotinic لثم وم يزكر لخدف علطی ھنا مویساتوبلا فقو اوج ریثك جراش فتیزوب Muscarinic receptor Prototypes of Agonists and Antagonists to Autonomic Receptors Adrenoreceptors Receptor Agonists (activator) Antagonists (inhibitor) α1 Norepinephrine Phenoxybenzamine Phenylephrine Prazosin α2 Clonidine Yohimbine β1 Norepinephrine Propranolol Isoproterenol Metoprolol β2 Epinephrine Propranolol Isoproterenol Butoxamine Albuterol Cholinoreceptors Nicotinic ACH Curare Nicotinic Carbachol Hexamethonium (blocks ganglionic receptor but not neuromuscular junction) Muscarinic ACH Atropine Muscarinic Carbachol Found in males slides only Large intestines Motility reduced Secretions and motility increased Liver Increased conversion of glycogen to glucose رمتسملا طغضلا( )ركسلا ضرم ببسی نكمم Kidney Decreased urine secretion Increased urine secretion Adrenal medulla Norepinephrine and epinephrine secrete Bladder Wall relaxed ,Sphincter closed Wall contracted ,Sphincter relaxed The Gastrointestinal Tract * Contains the enteric nervous system (one of the main divisions of ANS). decrease the activity of GI. increases the activity of GI tract, peristaltic contraction & sphincter relaxation. Systematic Blood Vessels constricts the vessels. - Dilation of skeletal muscles blood vessels - Constriction of skin blood vessels NO EFFECT except in certain areas. Eg: blushing of the face. Arterial Pressure increase of cardiac output + blood and pressure’s resistance. decreases cardiac output, BUT NO EFFECT ON BLOOD VESSELS. structure Sympathetic Stimulation Parasympathetic Stimulation Autonomic reflexes A) Cardiovascular: Baroreceptor reflex is a stretch reflex - longer & stronger - in the main arteries – such as carotid artery- which detects the blood pressure (When the pressure is high, sympathetic gets inhibited which stops the release of α1). D) Sexual reflexes: Parasympathetic à erection. Sympathetic à ejaculation. B) Gastrointestine: The receptors in the nose & mouth signals the parasympathetic system to notify the glands of mouth & stomach to secrete digestive juices. C) Urinary Bladder: Initiates the micturition - discharge of urine - by parasympathetic innervations. Most of the visceral functions of the body are regulated by autonomic reflexes. Found in males slides only Autonomic reflexes • The sympathetic activation could occur in isolated portions, such as: • Heart regulation. • Many Reflexes regulating G.I functions. The parasympathetic usually causes specific localized responses. Usualy to a certain organ, but sometimes it affects the function of some organs together, such as: • Rectal emptying + Bladder emptying. • Salivary secretion + Gastric secretion. Found in males slides only