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

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
Jean Nicot Nicotiana tobaccum
1530-1600
• Muscarinic: subtype of Acetycholine receptor
Amanita muscaria

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
7

8. 12 Cranial Nerves
• On Old Olympic Towering Tops A Finn And
German Viewed Some Hops
• Once One Openly Told Tourists About Fighting
Vampires Gobling Various Antelope Herds
• Oh Once One Takes The Anatomy Final Very
Good Vacations Are Heavenly
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 Nervous System
– Motor cell bodies in ventral horn
– Send axons to muscle
– Use Acetylcholine to stimulate

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

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

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 decreased (mildly)
Increased >
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- ACh Pre: ACh Pre: ACh
transmitter Post: NE, Ep Post: ACh
Receptor Nicotinic Pre: Nic Pre: Nic
Post: Adren 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