1. The AutonomicNervous System Lesson 15

2. Autonomic N. S. • Homeostasis • Maintenance of steady internal state • Effectors • autonomous • Smooth Muscle, Cardiac Muscle, Glands • Psychoactive drugs • autonomic effects common ~

3. Autonomic Subdivisions • Sympathetic • Emergency, flight/fight • Parasympathetic • Conservation / vegetative ~

4. Preganglionic neuron Postganglionic neuron Ganglion Autonomic N. S.: General Features Effector

5. Autonomic N. S.: General Features Effector ACh • At ganglia • Nicotinic receptors • different than neuromuscular • antagonist: hexamethonium ~

6. Autonomic N. S.: General Features Effector ACh • Neuroeffector junction • Different NT for each division ~

7. Pharmacology of Autonomic NS • Preganglionic neuron • releases ACh • Different NT at effectors • sympathetic division: NE • parasympathetic division: ACh ~

8. Sympatheticvs. Parasympathetic • Sympathetic • ganglia near spinal cord • interconnected  active together • long-lasting effects • Parasympathetic • ganglia near effector • discrete  active independently • transient effects • Antagonistic regulation ~

9. Pre- Post- Smooth muscle Glands NE Adrenal Glands Parasympathetic Sympathetic ACh

10. Sympathetic Arousal Syndrome • Fight or flight situations • Diffuse sympathetic activation • Adrenal glands • releases NE into blood • maintains sympathetic arousal • Parasympathetic rebound ~

11. Effector Responses Effector SympatheticParasympathetic Heart +- Respiration +- Salivation +(putrid)+(profuse) GI -+ Sweat glands +no input Iris +(radial)+(sphincter) ~

12. Autonomic N.S.: Summary • Parasympathetic • Conservation • Cholinergic • Discrete/short-lasting • Sympathetic • Emergency • Noradrenergic • Diffuse/long-lasting ~