Autonomic Nervous System

Transcription

1 Autonomic Nervous System Objectives 1. Describe the CNS components of the ANS 2. Understand the peripheral pathways that connect the ANS with targets in the body. 3. Understand the classes of disorders and types of symptoms resulting from autonomic disorders. Christopher Cohan, Ph.D. Dept. of Pathology/Anat Sci Jacobs School of Medicine

2 Autonomic Motor Components Control automatic functions of the body involving visceral organs, glands, blood vessels, non-voluntary muscles Motor portions of the ANS are 2 neuron pathways pregang CNS postgang PNS viscera

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4 Sympathetic Motor Overview Preganglionic cell bodies (CNS) Intermediolateral cell column (Thoraco-lumbar component: T1 - L2)

5 Sympathetic Motor Overview Postganglionic cell bodies (PNS) sympathetic chain ganglia prevertebral ganglia

6 Sympathetic Pathways Deep organs Sympathetic chain Paravertebral gang carotid Head, Thoracic Organs Eye- pupil Salivary Glands Lung Heart cardiac PostgangCB Sympathetic chain Route carotid n cardiac n Prevertebral gang celiac, sup/inf mesenteric

7 Sympathetic Pathways Deep organs Sympathetic chain Paravertebral gang splanchnic Abdom, Pelvic Organs GI Liver Pancreas **Adrenal-postgang cell body Visceral blood vessels Urinary System Uterus/penis Prevertebral gang celiac, sup/inf mesenteric PostgangCB Prevertebral gang Route splanchnic n

8 Sympathetic Pathways- Skin Limbs Blood Vessels: skin, mucosa Blood Vessels: skeletal muscle Sweat glands Piloerector muscle PostgangCB Sympathetic chain Route spinal n

9 Sympathetic Response Activated by fear, rage, fright fight or flight response prepares entire body for action ORGAN SYMPATHETIC PARASYMP Eye Heart Blood Ves - skin, mucosa, viscera Blood Ves - muscle Lung Liver Pancreas GI **Adrenal Urinary Sys - detruser sphincter Dilate Ý HR, contractility Constrict (Ý BP) Dilate Dilate Ý glycogenol/gluconeo Inhibits insulin release ß motil, secretion Epi release Relax Contract

10 Parasympathetic Motor Overview Preganglionic cell bodies (CNS) 1. Brainstem: CN III, VII, IX, X 2. Sacral Spinal Cord (S2-S4) (craniosacral components)

11 Parasympathetic Motor Overview Postganglionic cell bodies (PNS) ciliary, pterygopalatine, submandibular, otic ganglia abdom/pelvic terminal ganglia

12 Parasympathetic Pathways HEAD Cranial Nerves III VII IX CN III CN VII CN IX Eye- sphincter, ciliary body, lacrimal gland Salivary Glands

13 Parasympathetic Pathways CN X Thoracic/Abdominal Org Cranial Nerve X Lung Heart GI Liver

14 Parasympathetic Pathways Pelvic Organs Sacral Component Urinary System Repro System

15 CN III CN VII CN X CN IX Pregang Parasymp Brainstem Axons in CN Postgang CB Cell Bodies Location Edinger-Westphal Nuc midbrain CN III ciliary Superior Salivatory Nuc caudal pons CN VII pterygopalat. submandibuar Inferior Salivatory Nuc rostral medulla CN IX otic Dorsal Motor Nuc Vagus rostral medulla CN X terminal g

16 Parasympathetic Response Restorative function - homeostatic Action on specific organs as needed - localized ORGAN SYMPATHETIC PARASYMP Eye Dilate Constrict Heart Ý HR, contractility ß HR, contractility Blood Ves - skin, mucosa, viscera Constrict (Ý BP) (reflex ß BP) Blood Ves - muscle Dilate Lung Dilate Constrict Liver Ý glycogenol/gluconeo ß glycogenol/gluconeo GI ß motil, secretion Ý motil, secretion Urinary Sys - detruser sphincter Relax Contract Contract Relax

17 ANS Neurotransmitters ACh Nicotinic Receptor ACh Muscarinic Receptor ACh Parasympathetic division ACh Nicotinic Receptor Nicotinic Receptor ACh NE a, b adrenergic receptor *except sweat glands (ACh) Muscarinic Receptor Symp pregang ACh Nicotinic Receptor Adrenal E, NE

18 Sensory Components Sympathetic Sensory Fibers Few - mostly visceral pain fibers Parasympathetic Sensory Fibers Many - physiological information CN IX, X - monitor BP, O 2, CO 2, ph, gut distention Sacral bladder, bowel distention

19 Autonomic Disorders Autonomic symptoms can result from CNS Disorders Degenerative Disorders- Parkinson s Cortex lesions (frontal lobe) affecting hypothalamus, brainstem, spinal cord MS, syringomyelia, Chiari malformation, Horner s, amyotrophic lateral sclerosis PNS Neuropathies autoimmune, diabetic, toxic

20 Autonomic Disorders ANS has long nerves connecting CNS components with organs PNS neuropathies affect Abnormal sweating Temp Control- difficulty sweating, shivering, vasoconstriction Bladder- incontinence, difficulty sensing fullness, difficulty emptying GI- constipation, diarrhea, bloating, appetite loss Eyes- dry mouth/eyes, constricted pupil, blurry vision Sexual Function- male impotence, difficulty with orgasm tachycardia/bradycardia- difficulty exercising, orthostatic hypotension