Introduction to the PNS

This presentation was delivered to 1st year pharmacy students and accompanies and accompanies Goodman & Gilman's (12e) chapter 8.

1. Peripheral Nervous System Brian J. Piper, Ph.D., M.S.

2. The Nervous System ------------------------------- Enteric (digestive)

3. Goals Anatomy & Physiology of: Somatic Nervous System Autonomic Nervous System

4. 4 Meninges of the Spinal Cord Spinal cord Spinal cord Pia mater Arachnoid mater Dura mater Dorsal root Dorsal root Spinal nerve Epidural space (a) (b) Ventral root Dorsal root ganglion Thoracic vertebra Spinal nerve Dorsal root ganglion Subarachnoid space Dorsal branch (dorsal ramus) Ventral branch (ventral ramus) Ventral root Epidural space Body of vertebra

5. Refresher I Afferent: towards center (brain), ≈sensory Efferent: away from center (brain), ≈motor Ganglia: mass of cell bodies Plexus: network of neurons

6. Refresher II Nicotinic: subtype of Acetycholine receptor 1530-1600 Muscarinic: subtype of Acetycholine receptor Jean Nicot Nicotiana tobaccum Amanita muscaria

7. 7 Peripheral Nervous System Cranial nerves arising from the brain Somatic fibers connecting to the skin and skeletal muscles Autonomic fibers connecting to viscera Spinal nerves arising from the spinal cord Somatic fibers connecting to the skin and skeletal muscles Autonomic fibers connecting to viscera

8. 12 Cranial Nerves O n O ld O lympic T owering T ops A F inn A nd G erman V iewed S ome H ops O nce  O ne  O penly  T old  T ourists  A bout  F ighting V ampires   G obling   V arious  A ntelope  H erds O h  O nce  O ne  T akes  T he  A natomy  F inal  V ery  G ood   V acations  A re  H eavenly http://en.wikipedia.org/wiki/List_of_mnemonics_for_the_cranial_nerves

9. CN I: Olfactory Connect nasal cavity to temporal cortex Substantial individual differences Forms new neurons throughout life!

10. CN II: Optic Connects retina to thalamus (lateral geniculate nucleus) Partial decussation

11. CN VIII: Vestibulocochlear (Auditory) Connects cochlea to brainstem Responsible for balance & hearing

12. Somatic Nervous System Voluntary N ervous System Motor cell bodies in ventral horn Send axons to muscle Use Acetylcholine to stimulate

13. Autonomic NS: Two Neurons ACh Howland & Mycek (2006). Lippincott’s Illustrated Reviews: Pharmacology. p. 36. ACh : Acetylcholine

14. Autonomic Nervous System Autonomous “automatic” Functions: blood pressure, heart rate, sleep, bladder & bowel function Sympathetic NS: “fight or flight” Parasympathetic NS: “rest & maintain” Medulla: Epinephrine Cortex: Cortisol Walter Cannon

15. Automobile Analogy

16. Functional Consequences of Normal ANS Function Sympathetic Parasympathetic Heart Rate Increased Decreased Blood pressure Increased Decreased Bowel motility Decreased Increased Lung Bronchodilation Bronchoconstriction Pupils Dilation Constriction Adrenal glands Catecholamine release - Sexual function (males) Orgasm Erection Bladder Increased sphincter tone Decreased sphincter tone Parotid gland - Salivation Low & Engstrom (2012). Disorders of the ANS. In Harrison’s VII, Ch 375, p. 3352.

17. Unbalanced Sympathetic Parasympathetic Heart Rate Increased < Decreased Blood pressure Increased > decreased (mildly) Bowel motility Decreased Increased Lung Bronchodilation Bronchoconstriction Pupils Dilation Constriction Adrenal glands Catecholamine release - Sexual function (males) Orgasm Erection Bladder Increased sphincter tone < Decreased sphincter tone Parotid gland - Salivation Low & Engstrom (2012). Disorders of the ANS. In Harrison’s VII, Ch 375, p. 3352.

18. Sympathetic & Parasympathetic Innervation I Central components “accident” example All at once ( Sym ) versus individual components (PS)

19. Sympathetic versus Parasympathetic Preganlionic projection: short long

20. Comparison Sympathetic Parasympathetic Origin T1 to T12, L1, L2 CN III, VII, IX, X, S2, S3 Target organs Diffuse Localized Transmitter Adrenergic Muscarinic Amplification Yes (1:20) No (1:1)

21. Comparison of Somatic and Autonomic Nervous Systems Somatic Sympathetic ParaSymp # neurons 1 > 1 2 Myelinated Yes Pre-Gang Pre-Gang Neuro - transmitter ACh Pre: ACh Post: NE, Ep Pre: ACh Post: ACh Receptor Nicotinic Pre: Nic Post: Adren Pre: Nic Post: mus

22. Light Reading O:15 to 3:58: http://www.youtube.com/watch?v=sPS7GnromGo

23. ANS (Stress) & Health Top Causes of Death (2009): 1) Heart Disease 2) Cancer 3) Chronic respiratory diseases 4) Stroke 5) Accidents 6) Alzheimer’s 7) Diabetes 8) Influenza & pneumonia 9) Kidney disease 10) Suicide http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_04.pdf