The Autonomic Nervous System Autonomic control areas in

The Autonomic Nervous System

Autonomic control areas in the brain stem and hypothalamus

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Sympathetic Nerve Fibers in the Skeletal Nerves 4

Prevertebral (Collateral) Celiac (Solar plexus) Sup. Mesenteric Inf. Mesenteric Pelvic-hypogastric plexus Adrenal medulla: sympathetic prevertebral ganglion Amplification Slower to arrive Slower to dissipate Lack the point to point specificity of other SNS projections 5

Parasympathetic 6

Points Sympathetic Parasympathetic Catabolic Anabolic Distant from target organ Near or in target organ Length of preganglionic axon Relatively short Relatively long Divergence of preganglionic axonal projection One to many One to few Innervate trunk and limbs in addition to viscera Yes No Postganglionic transmitter NE Ach Functions Location of Ganglion 7

Ach receptors • Nicotinic Ion channel receptor (Na+ and K+); • Muscarinic N 1, N 2 G protein-coupled receptor M 1, M 3, M 5 (PLC) M 2, M 4 (inhibition of AC) 8

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Co-tranmission • ATP and neuropeptide Y co-release with NE. • VIP with Ach • In ganglions: Ach- N 2 - rapid EPSP Ach- M- slow EPSP

Termogenesis (β 3)

Components of autonomic reflexes arcs: – sensory receptor – sensory neuron – integrating center – pre & postganglionic motor neurons – visceral effectors 15

Horner's syndrome 16