Autonomic Nervous System (ANS) Assoc. Prof. Wantanee Trakulrungsi Department of Anatomy, Faculty of Science, Mahidol University.

Autonomic Nervous System (ANS) Sympathetic Nervous System (Thoracolumbar division Or Adrenergic division) Parasympathetic Nervous System (Craniosacral division Or Cholinergic division)

Comparision of the somatic and autonomic nervous system.

Sympathetic pathways (a) Synapse in a sympathetic chain ganglion at the same level.(b) Synapse in a sympathetic chain ganglion at a different level. (c)Synapse in a collateral ganglion anterior to the vertebral column.

Terms -Preganglionic sympathetic neurons: In intermediolateral cell column of T1-L2 spinal cord segments -Preganglionic sympathetic fibers -Postganglionic sympathetic neurons: In the sympathetic ganglion. -Postganglionic sympathetic fibers. -White ramus communicans. -Gray ramus communicans. -Splanchnic nerves

Sympathetic ganglion 1. Paravertebral ganglion : Locate beside the vertebral column (In sympathetic chain) Superior Cervical Ganglion (SCG) - Cervical ganglion 3 pair Middle Cervical Ganglion (MCG) Inferior Cervical Ganglion (ICG) - Thoracic ganglion12 pair - Lumbar ganglion 4 (5) pair - Sacral ganglion 4 (5) pair - Coccygeal ganglion1 ganglion (single) called ganglion impar Stellate ganglion (ICG + T 1 ganglion)

Sympathetic ganglion 2. Prevertebral ganglion - Celiac ganglion - Superior mesenteric ganglion - Inferior mesenteric ganglion - Superior hypogastric ganglion - Inferior hypogastric ganglion

Sympathetic ganglion Paravertebra l ganglion Prevertebral ganglion

Postganglionic sympathetic fibers 1. Travel along the spinal nerves. 2. Travel along the blood vessel, e.g. internal carotid artery. 3. Travel straight to the target organ.e.g. fibers to the heart.

Perivascular plexus - Sympathetic : postganglionic sympathetic fibers -Parasympathetic : preganglionic parasympathetic fibers - Sensory fibers

Pain - visceral pain or real pain - Referred pain

Splanchnic nerve (= preganglionic sympathetic fibers) - Thoracic splanchnic nerve - Lumbar splanchnic nerve - Sacral splanchnic nerve

Thoracic splanchnic nerve 1. Greater sp.n. : Preganglionic sympathetic fibers that pass through the T5- T9 ganglia without synapse synapse at celiac ganglion 2. Lesser sp.n. : pass through T10,T11 ganglion without synapse synapse at Aorticorenal ganglion 3. Lowest sp.n.: pass through T12ganglion without synapse synapse at renal plexus

Lumbar splanchnic nerve L 1 ganglionintermesenteric ganglion L 2 ganglion L 3 ganglion superior hypogastric L 4 gangion ganglion at the bifurcation of Aorta

Sacral splanchnic nerve S 1 ganglion S 2 ganglion synapse at Inferior hypogastric ganglion in S 3 ganglionpelvic cavity S 4 ganglion

Lumbar and Sacral Splanchnic nerves

Parasympathetic Nervous System (Craniosacral Outflow or Cholinergic Outflow) Cranial part: From parasympath etic nucleus of CN III, VII, IX, X Spinal part: From the intermediolat eral gray column of S2- S4

Parasympathetic nervous system of the Head and Neck

Parasympathetic of CNIII * Preganglionic parasympathetic neurons locate at the Edinger-Westphal nucleus. * Preganglionic parasympathetic fibers pass along CNIII CNIII to the inferior oblique muscle * Synapse at Ciliary ganglion. * Postganglionic parasympathetic fibers go to 1. Pupillary constrictor muscles of iris and 2.Ciliary muscles of ciliary body

Parasympathetic of CNVII I * Preganglionic parasympathetic neurons locate at the Superior salivatory nucleus * Preganglionic parasympathetic fibers pass along tympani CNVII (Nervous intermediate) Chorda tympani nerve * Synapse at Submandibular ganglion. * Postganglionic parasympathetic fibers go to 1. Submandibular salivary gland and 2. Sublingual salivary gland

Parasympathetic of CNVII II. * Preganglionic parasympathetic neurons locate at the Superior salivatory nucleus * Preganglionic parasympathetic fibers pass along CNVII (Nervous intermediate) Greater superficial petrosal nerve Nerve of pterygoid canal (Vidian nerve) * Synapse at Pterygopalatine ganglion. * Postganglionic parasympathetic fibers go to 1.Lacrimal gland and 2.Mucous glands of Nose, palate and pharynx

-Superior salivatory nucleus -Submandibular ganglion -Pterygopalatine ganglion

Parasympathetic of CNIX * Preganglionic parasympathetic neurons locate at the Inferior salivatory nucleus * Preganglionic parasympathetic fibers pass along CNIX tympanic nerve tympanic plexus lesser superficial petrosal nerve * Synapse at Otic ganglion. * Postganglionic parasympathetic fibers go to Parotid salivary gland

-Inferior salivatory nucleus -Otic ganglion -Parotid salivary gland

Parasympathetic of CNX -Dorsal motor nucleus of vagus nerve -Preganglionic parasympathetic fibers travel along the vagus nerve. -Postganglionic parasympathetic neurons locate near or within the wall of the effector organs e.g. Myenteric ganglia of GI tract -Postganglionic parasympathetic fibers end at the smooth muscle of the GI tract

1. What is the name of the nucleus? 2. Preganglionic parasympathetic fibers travel along which cranial nerve? 3. What is the name of the parasympathetic ganglion? Where is it located? 4.Postganglionic parasympathetic fibers hitch a ride with which branch of which nerve? 5.What is the effector organ? 6.What happens to that organ?

Effects of the Sympathetic and Parasympathetic Divisions of the Autonomic Nervous system

Autonomic innervation 1. opposite effect = dual, antagonistic autonomic innervation e.g. Heart sti.parasym (from vagus nerve)car cardiac deceleration or bradycardia * slowing of the beat * reduction in the force of contraction * reduction in the ventricular output (blood volume per beat) sti.symp. (cardiac nerve from the cervical ganglia) cardiac acceleration or tachycardia * in contractile force * in volume of blood pumped per beat

2. Dual but different effect e.g. salivary gland sti. Symp. produces a thick mucus secretion sti. Parasymp. Produces copious of a clear, watery,serous secretion 3 Receive innervation from only one of the division e.g. sweat gland and erector pili muscles symp. No antagonistic or different effect is noted.

References 1) Marieb,E.N.: Essentials of Human Anatomy & Physiology, Sixth Edition, Addison Wesley Longman, Inc., ) Moore, K.L. and Anne M.R. Agur. Essential Clinical Anatomy, Second Edition, Lippincott Williams & Wilkins, ) Burt, A.M. Textbook of Neuroanatomy, chapter 18. W.B. Saunders Company, 1993.