1. Peripheral Nervous System

2. I. Composed of Nerves
A. Bundle of neurons surrounded by connective tissue

3. B. Classification of nerves 1
B. Classification of nerves 1. Sensory/Afferent – composed entirely of sensory neurons 2. Motor/Efferent – composed entirely of motor neurons 3. Mixed – composed of both sensory and motor neurons

4. II. Divided into 2 subcomponents
Somatic and Autonomic Nervous Systems
Somatic – voluntary control of skeletal muscles
Autonomic – involuntary control of smooth muscle, cardiac muscle, and glands

5. Somatic Autonomic Voluntary? Effectors Neurotransmitters Usually Never
Skeletal Muscles
Glands, smooth muscle, cardiac muscle
Neurotransmitters
Acetylcholine – always!
Acetylcholine, epinephrine, norepinephrine

6. III. Autonomic Nervous System
A. Controls involuntary responses to regulate physiological responses B. Further divided into Sympathetic and Parasympathetic divisions

7. Sympathetic division –
“Fight or Flight”
a. Nerves originate from center of spinal cord
b. Uses epinephrine and norepinephrine as neurotransmitters

8. c. Response to unusual circumstances – increases activity d
c. Response to unusual circumstances – increases activity d. “E” division – exercise, excitement, emergency, embarrassment
Sympathetic = Snake

9. 2. Parasympathetic division – “Rest and digest” a
2. Parasympathetic division – “Rest and digest” a. Nerves originate from the brain stem and upper and lower parts of the spinal cord b. Uses acetylcholine as neurotransmitter

10. Parasympathetic = Panda
c. Conserves energy and handles the usual circumstances d. “D” division – digestion, defecation, diuresis
Parasympathetic = Panda

11. IV. Cranial Nerves
Peripheral nerves that arise from the brain instead of the spinal cord
For the most part control parts things from the neck up (vagus nerve is the exception)

12. I – Olfactory – sensory, smell

13. II – Optic – sensory, vision

14. III – Oculomotor – motor, eye muscles – moves eyelids and eyeball, adjusts pupils and lenses

15. IV – Trochlear, motor, moves eyeballs

16. V – Trigeminal – sensory for face, motor for chewing

17. VI – Abducens – motor, moves eyeballs

18. VII – Facial
Sensory – taste
Motor - face

19. VIII – Vestibulocochlear
Sensory – balance and hearing

20. IX – Glossopharyngeal
Sensory – taste
Motor – pharynx (swallowing)

21. X – Vagus sensory & motor, throat and internal organs

22. XI – Accessory – motor, neck & upper back

23. XII – Hypoglossal – motor, tongue