1. Human Anatomy The Autonomic Nervous System ANS

2. Regulates various physiological processes unconsciously, for instance: 1.Cardiovascular 2.Respiration 3.Digestion 4.Body temperature 5.Excretion

3. 2 Subdivisions of the ANS 1.Sympathetic NS “fight or flight” 2.Parasympathetic NS “rest and repose”

4. Anatomy of ANS Consists of only 2 neurons 1.Preganglionic neuron (#1) 2.Ganglionic neuron (#2) The ganglion is a structure where the axon of the preganglionic neuron synapses (release of neurotransmitter) with the ganglionic neuron (dendrite or cell body) The axon of the ganglion synapses with the target cell or organ.

5. Anatomy of the ANS Differences between sympathetic and parasympathetic are: 1.Location of preganglionic (#1) cell body 2.Location of the ganglia 3.Neurotransmitters released at synapses 4.Effects on target organs

6. Sympathetic Anatomy Once again, just 2 cells Preganglion (#1) cell body in gray matter of spinal cord ---- levels T 1 – L 2 Thoracolumbar system

7. Sympathetic Anatomy Thoraco- lumbar

8. Sympathetic Anatomy Synapse of preganglionic (#1) with ganglionic (#2) neurons happens in the ganglion 3 cervical ganglia 3 abdominal ganglia Neurotransmitter is acetylcholine (ACh)

9. Sympathetic Anatomy Thoraco- lumbar

10. Sympathetic Ganglia Paravertebral ganglia 1.Cervical Superior Middle Inferior 2.Abdominal Celiac Superior mesenteric Inferior mesenteric

11. Sympathetic Anatomy Thoraco- lumbar

12. Sympathetic Anatomy Ganglionic (#2) axons are relatively long Synapse at target cell or organ Neurotransmitter is norepinephrine (NE)

13. Sympathetic Anatomy Thoraco- lumbar

14. Parasympathetic Anatomy Once again, just 2 cells Preganglionic (#1) cell body in either: 1.Brainstem 2.Spinal cord ---- S 2 – S 4 Craniosacral system

15. Parasympathetic Anatomy Cranio- sacral

16. Parasympathetic Anatomy Synapse of preganglionic with ganglionic neurons happens in the ganglion Ganglia are located on the target organs

17. Parasympathetic Anatomy Cranio- sacral

18. Parasympathetic Anatomy Ganglionic axons are relatively short Synapse at target cell or organ Neurotransmitter is acetylcholine (ACh)

19. Parasympathetic Anatomy Cranio- sacral

20. Summary FIGURE 17-2 p. 445

21. Summary Sympathetic 1.Thoracolumbar 2.Paravertebral ganglia 3.ACh then NE Parasympathetic 1.Craniosacral 2.Ganglia at target 3. ACh and ACh

22. Biological Effects Most organs have dual innervation 1.CV S – increase heart rate, force of ventricle contraction, increase blood pressure by constricting smooth muscles of arteries P -- opposite

23. Biological Effects 2.Respiration S – dilation of bronchiole smooth muscle which increases diameter P – opposite 3.Digestion S – decreases activity of organs and glands P -- opposite

24. Biological Effects 4.Vision S – dilation of pupil P – constriction of pupil 5.Reprodction S – causes ejaculation in males P – sexual arousal (erection) in both sexes