1. Spinal Cord & Peripheral Nervous System Anatomy Lesson 6

2. Dorsal Ventral Horns Spinal Cord

3. n Dorsal root ganglion (DRG) l Sensory input n Ventral root l Motor output ~

4. Peripheral N. S. n Cranial Nerves - 12 pair n Spinal Nerves - 31 pair n Somatic Division l Sensory information l Body Movement n Autonomic division - Homeostasis l regulation ~

5. Cranial Nerves n Ventral surface of brain l Olfactory – frontal lobe l Optic – thalamus l All others from brainstem n Functions l Sensory & motor (head/neck) l Homeostasis (abdomen) n Optic nerves l NOT part of PNS ~

6. Spinal Nerves n 1 pair for each vertebral segment n 8 cervical (C1-C8) n 12 thoracic (T1-T12) n 5 lumbar (L1-L5) n 5 sacral (S1-S5) n 1 coccygeal ~

7. Spinal Nerves n Thoracic nerves relatively small u back & ribs n Cervical, lumbar, & sacral: large nerves u rest of the body n Dermatomes l Receptive fields of body l Overlap  redundancy ~

8. Somatic N. S. - Motor Spinal Cord Motor Neuron n Striate muscle l nerve-dependent l uninterrupted neuron l excitatory only n Neurotransmitter l Acetylcholine (Ach) ~ Effector +

9. Autonomic N. S. n Homeostasis l Not nerve-dependent n Effectors l Smooth Muscle l Cardiac Muscle l Glands ~

10. Autonomic Subdivisions n Sympathetic l Emergency, flight/fight n Parasympathetic l Conservation / vegetative ~

11. Effector Ganglion Preganglionic neuron Postganglionic neuron Autonomic: General Features ACh

12. Pharmacology of Autonomic NS n Preganglionic neuron l releases ACh l Different NT at effectors n Parasympathetic division l Acetylcholine (Ach) n Sympathetic division: l Norepinephrine (NE) ~

13. Sympathetic vs. Parasympathetic n Sympathetic l ganglia near spinal cord l interconnected  active together l long-lasting effects n Parasympathetic l ganglia near effector l discrete  active independently l transient effects n Antagonistic regulation ~

14. Effector Responses Effector Sympathetic Parasympathetic Heart   Respiration   GI   Immune system   Iris  (radial)  (sphincter) Sweat glands  no input Adrenal glands  no input ~

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

16. Sympathetic Arousal Syndrome n Fight or flight situations l Diffuse sympathetic activation n Adrenal glands l releases NE into blood l maintains sympathetic arousal n Parasympathetic rebound n Stress & health ~