1. Copyright © 2010 Pearson Education, Inc. Central nervous system (CNS)Peripheral nervous system (PNS) Motor (efferent) division Sensory (afferent) division Somatic nervous system Autonomic nervous system (ANS) Sympathetic division Parasympathetic division Figure 14.1

2. Copyright © 2010 Pearson Education, Inc. Skeletal muscle Cell bodies in central nervous system Peripheral nervous systemEffect + + Effector organs ACh Smooth muscle (e.g., in gut), glands, cardiac muscle Ganglion Adrenal medullaBlood vessel ACh NE Epinephrine and norepinephrine Acetylcholine (ACh)Norepinephrine (NE) Ganglion Heavily myelinated axon Lightly myelinated preganglionic axon Lightly myelinated preganglionic axons Neuro- transmitter at effector Unmyelinated postganglionic axon Unmyelinated postganglionic axon Stimulatory or inhibitory, depending on neuro- transmitter and receptors on effector organs Single neuron from CNS to effector organs Two-neuron chain from CNS to effector organs SOMATIC NERVOUS SYSTEM AUTONOMIC NERVOUS SYSTEM PARASYMPATHETIC SYMPATHETIC Figure 14.2

3. Copyright © 2010 Pearson Education, Inc. ANS Anatomy

4. Copyright © 2010 Pearson Education, Inc. Salivary glands Eye Skin* Heart Lungs Liver and gall- bladder Genitals Pancreas Eye Lungs Bladder Liver and gall- bladder Pancreas Stomach Cervical Sympathetic ganglia Cranial Lumbar Thoracic Genitals Heart Salivary glands Stomach Bladder Adrenal gland ParasympatheticSympathetic Sacral Brain stem L1L1 T1T1 Figure 14.3

5. Copyright © 2010 Pearson Education, Inc. Pterygopalatine ganglion Eye Lacrimal gland Nasal mucosa Ciliary ganglion Pterygopalatine ganglion Submandibular ganglion Submandibular and sublingual glands CN III CN VII CN IX CN X Otic ganglion Parotid gland Heart Lung Liver and gallbladder Stomach Pancreas Urinary bladder and ureters Small intestine Large intestine S2S2 Pelvic splanchnic nerves Genitalia (penis, clitoris, and vagina) Rectum Celiac plexus Inferior hypogastric plexus Cardiac and pulmonary plexuses S4S4 Preganglionic Postganglionic Cranial nerve Figure 14.4

6. Copyright © 2010 Pearson Education, Inc. Sympathetic (Thoracolumbar) Division Preganglionic neurons are in spinal cord segments T 1 – L 2 Sympathetic neurons produce the lateral horns of the spinal cord

7. Copyright © 2010 Pearson Education, Inc. Figure 14.6 Superior cervical ganglion Middle cervical ganglion Inferior cervical ganglion Sympathetic trunk (chain) ganglia Pons L2L2 T1T1 White rami communicantes Liver and gallbladder Stomach Spleen Kidney Adrenal medulla Small intestine Large intestine Genitalia (uterus, vagina, and penis) and urinary bladder Celiac ganglion Inferior mesenteric ganglion Lesser splanchnic nerve Greater splanchnic nerve Superior mesenteric ganglion Lumbar splanchnic nerves Eye Lacrimal gland Nasal mucosa Blood vessels; skin (arrector pili muscles and sweat glands) Salivary glands Heart Lung Rectum Cardiac and pulmonary plexuses Preganglionic Postganglionic Sacral splanchnic nerves

8. Copyright © 2010 Pearson Education, Inc. Figure 14.5a Spinal cord Dorsal root Ventral root Sympathetic trunk ganglion Sympathetic trunk Rib Ventral ramus of spinal nerve Gray ramus communicans White ramus communicans Thoracic splanchnic nerves (a) Location of the sympathetic trunk

9. Copyright © 2010 Pearson Education, Inc. Figure 14.7 Spinal cord Dorsal root ganglion Autonomic ganglion Stimulus Response Visceral sensory neuron Integration center May be preganglionic neuron (as shown) May be a dorsal horn interneuron May be within walls of gastrointestinal tract Sensory receptor in viscera 2 3 1 5 Visceral effector Efferent pathway (two-neuron chain) Preganglionic neuron Ganglionic neuron 4

10. Copyright © 2010 Pearson Education, Inc. Referred Pain Visceral pain afferents travel along the same pathway as somatic pain fibers Pain stimuli arising in the viscera are perceived as somatic in origin

11. Copyright © 2010 Pearson Education, Inc. Figure 14.8 Heart Lungs and diaphragm Liver Stomach Kidneys Ovaries Small intestine Ureters Urinary bladder Colon Pancreas Liver Heart Appendix Gallbladder

12. Copyright © 2010 Pearson Education, Inc. Neurotransmitters Cholinergic fibers release ACh All ANS preganglionic axons All parasympathetic postganglionic axons Adrenergic fibers release NE Most sympathetic postganglionic axons Exceptions: sympathetic fibers secrete ACh at sweat glands, some blood vessels in skeletal muscles

13. Copyright © 2010 Pearson Education, Inc. Figure 14.2 + ACh Smooth muscle (e.g., in gut), glands, cardiac muscle Ganglion Adrenal medullaBlood vessel ACh NE Epinephrine and norepinephrine Acetylcholine (ACh)Norepinephrine (NE) Ganglion Lightly myelinated preganglionic axon Lightly myelinated preganglionic axons Unmyelinated postganglionic axon Unmyelinated postganglionic axon Stimulatory or inhibitory, depending on neuro- transmitter and receptors on effector organs Two-neuron chain from CNS to effector organs AUTONOMIC NERVOUS SYSTEM PARASYMPATHETIC SYMPATHETIC

14. Copyright © 2010 Pearson Education, Inc. Receptors for Neurotransmitters 1.Cholinergic receptors for ACh 2.Adrenergic receptors for NE

15. Copyright © 2010 Pearson Education, Inc. Cholinergic Receptors Two types of receptors bind ACh 1.Nicotinic 2.Muscarinic Named after drugs that bind to them and mimic ACh effects

16. Copyright © 2010 Pearson Education, Inc. Nicotinic Receptors Found on Motor end plates of skeletal muscle All ganglionic neurons (sympathetic and parasympathetic) Hormone-producing cells of adrenal medulla Effect of ACh at nicotinic receptors is always stimulatory

17. Copyright © 2010 Pearson Education, Inc. Muscarinic Receptors All effector cells stimulated by postganglionic cholinergic fibers The effect of ACh at muscarinic receptors Can be inhibitory or excitatory Depends on receptor type of target organ

18. Copyright © 2010 Pearson Education, Inc. Table 14.2

19. Copyright © 2010 Pearson Education, Inc. Adrenergic Receptors Two types Alpha (  ) (subtypes  1,  2) Beta (  ) (subtypes  1,  2,  3) Effects of NE depend on which subclass of receptor on the target organ

20. Copyright © 2010 Pearson Education, Inc. Table 14.2

21. Copyright © 2010 Pearson Education, Inc. Effects of Drugs Atropine Anticholinergic; blocks muscarinic receptors Prevent salivation during surgery, and dilates pupils for exam Neostigmine Inhibits acetylcholinesterase Used to treat myasthenia gravis

22. Copyright © 2010 Pearson Education, Inc. Effects of Drugs OTC for colds, allergies, and nasal congestion Stimulate  -adrenergic receptors Beta-blockers Attach to  2 receptors to dilate lung bronchioles in asthmatics

23. Copyright © 2010 Pearson Education, Inc. Table 14.3

24. Copyright © 2010 Pearson Education, Inc. Sympathetic Tone Sympathetic controls BP at rest Sympathetic tone (vasomotor tone) Keeps BV in a continual state of partial constriction Alpha-blocker drugs interfere with vasomotor fibers and are used to treat hypertension

25. Copyright © 2010 Pearson Education, Inc. Parasympathetic Tone Parasympathetic dominates heart and smooth muscle of digestive and urinary tract organs Slows heart Dictates normal activity levels of digestive and urinary tracts Sympathetic can override effects during stress Block parasympathetic increase heart rate and block fecal and urinary retention

26. Copyright © 2010 Pearson Education, Inc. Unique Roles of the Sympathetic Division Adrenal medulla, sweat glands, arrector pili muscles, kidneys, and most BV receive only sympathetic fibers Sympathetic controls Thermoregulatory responses to heat Release renin from kidneys Metabolic effects Increases metabolic rate Raises blood glucose Mobilizes fats for use as fuels

27. Copyright © 2010 Pearson Education, Inc. Effects of Sympathetic Activation Sympathetic is long lasting because NE Is inactivated more slowly than ACh NE and epinephrine released into blood and remain until destroyed by liver

28. Copyright © 2010 Pearson Education, Inc. Control of ANS Functioning Hypothalamus—integrative center of ANS Subconscious input via limbic lobe

29. Copyright © 2010 Pearson Education, Inc. Figure 14.9 Cerebral cortex (frontal lobe) Limbic system (emotional input) Communication at subconscious level Hypothalamus Overall integration of ANS, the boss Spinal cord Urination, defecation, erection, and ejaculation reflexes Brain stem (reticular formation, etc.) Regulation of pupil size, respiration, heart, blood pressure, swallowing, etc.

30. Copyright © 2010 Pearson Education, Inc. Hypothalamic Control Control may be direct or indirect (through the reticular system) Centers of the hypothalamus control Heart activity and blood pressure Body temperature, water balance, and endocrine activity Emotional stages (rage, pleasure) and biological drives (hunger, thirst, sex) Reactions to fear and the “fight-or-flight” system

31. Copyright © 2010 Pearson Education, Inc. Developmental Aspects of the ANS During youth, ANS impairments are usually due to injury In old age, ANS efficiency declines, partially due to structural changes at preganglionic axon terminals

32. Copyright © 2010 Pearson Education, Inc. Developmental Aspects of the ANS Effects of age on ANS Constipation Dry eyes Frequent eye infections Orthostatic hypotension Low BP occurs because aging pressure receptors respond less to changes in BP with changes in body position and because of slowed responses by sympathetic vasoconstrictor centers