1. Pages 264-269

2. Central Nervous System (brain and spinal cord) Peripheral Nervous System (cranial and spinal nerves) Somatic (voluntary) Autonomic (involuntary) Sensory (afferent) Motor (efferent) Sense organs Skeletal muscles Cardiac and smooth muscle, glands Parasympathetic Sympathetic

3.  The relative stability of our internal environment depends largely on ANS function  Involuntary regulation of ◦ Cardiac activity ◦ Smooth muscles/glands  Two subdivisions: 1.Sympathetic division 2.Parasympathetic division © 2015 Pearson Education, Inc.

4.  The ANS has a chain of two motor neurons ◦ Preganglionic neuron : exists in brain or spinal cord  Axon is myelinated ◦ Postganglionic neuron:  outside the CNS  Extends to a specific organ  Axon is un-myelinated = slower response  This arrangement is different from the somatic division (voluntary motor division) which has only one motor neuron

5. Central nervous system Peripheral nervous system Effector organs Acetylcholine Skeletal muscle Acetylcholine Norepinephrine Ganglion Acetylcholine Epinephrine and norepinephrine Blood vessel Acetylcholine Ganglion Smooth muscle (e.g., in stomach) Glands Cardiac muscle Somatic nervous system Autonomic nervous system Sympathetic division Para- sympathetic division KEY: Preganglionic axons (sympathetic) Postganglionic axons (sympathetic) Myelination Preganglionic axons (parasympathetic) Postganglionic axons (parasympathetic)

6.  Acetylcholine (Ach) is released in both divisions ◦ ACh is released by the Parasympathetic division to stimulate the effector directly ◦ ACh is released by the Sympathetic division to cause a release of:  Epinephrine by the adrenal gland  Norepinephrine by the postganglionic nerve fibers  Either of these neurotransmitters will stimulate the effector (heart, blood vessel, gland…)

7. Eye Salivary glands Heart Lungs Stomach Pancreas Liver and gall- bladder Bladder Genitals Cervical T1T1 Thoracic L1L1 Lumbar Brain stem Cranial Sympathetic ganglia Sacral nerves (S 2 –S 4 ) ParasympatheticSympathetic Skin Salivary glands Heart Lungs Stomach Pancreas Liver and gall- bladder Bladder Genitals Adrenal gland

8. REST/DIGESTFIGHT/FLIGHT  PARASYMPATHETIC  Relaxes  Conserves  Neurotransmitter at work is ACh  SYMPATHETIC  Mobilizes  Triggers: ◦ Fear, exercise, rage  Neurotransmitters at work are ◦ Epinephrine ◦ Norepinephrine ◦ Acetylcholine

9. PNS: Differences Between Somatic and Autonomic Nervous Systems © 2015 Pearson Education, Inc. Somatic Nervous System Autonomic Nervous System NervesOne-neuron system; it originates in the CNS, and axons extend to the skeletal muscles served Two-neuron system consisting of preganglionic and postganglionic neurons Effector organSkeletal muscleSmooth muscle, cardiac muscle, glands SubdivisionsNoneSympathetic and parasympathetic NeurotransmitterAcetylcholine Acetylcholine, epinephrine (adrenaline), norepinephrine