Chapter 9 The Peripheral and Autonomic Nervous System Edited by Dr. Ryan Lambert-Bellacov

Peripheral Nervous System Nerves that connect the brain and spinal cord with sensory receptors, muscles, and glands Afferent peripheral system Efferent peripheral system

Efferent Peripheral System Somatic nervous system Autonomic nervous system –Sympathetic –Parasympathetic Edited by Dr. Ryan Lambert-Bellacov

Neuron Anatomy Slide 7.9b  Cell body  Nucleus  Large nucleolus Figure 7.4a Edited by Dr. Ryan Lambert-Bellacov

Nerves Bundles of nerve fibers enclosed by connective tissue –Sensory or afferent nerves –Motor or efferent nerves –Mixed nerves

Neuron Classification Slide 7.15 Figure 7.6

Neuron Cell Body Location Slide 7.13  Most are found in the central nervous system  Gray matter – cell bodies and unmylenated fibers  Nuclei – clusters of cell bodies within the white matter of the central nervous system  Ganglia – collections of cell bodies outside the central nervous system

How Neurons Function (Physiology) Slide 7.17  Irritability – ability to respond to stimuli  Conductivity – ability to transmit an impulse  The plasma membrane at rest is polarized  Fewer positive ions are inside the cell than outside the cell

Starting a Nerve Impulse Slide 7.18 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Depolarization – a stimulus depolarizes the neuron’s membrane  A deploarized membrane allows sodium (Na + ) to flow inside the membrane  The exchange of ions initiates an action potential in the neuron Figure 7.9a–c

The Action Potential Slide 7.19 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  If the action potential (nerve impulse) starts, it is propagated over the entire axon  Potassium ions rush out of the neuron after sodium ions rush in, which repolarizes the membrane  The sodium-potassium pump restores the original configuration  This action requires ATP

Nerve Impulse Propagation Slide 7.20  The impulse continues to move toward the cell body  Impulses travel faster when fibers have a myelin sheath Figure 7.9c–e

How Neurons Communicate at Synapses Slide 7.22 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 7.10

The Reflex Arc Slide 7.23 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Reflex – rapid, predictable, and involuntary responses to stimuli  Reflex arc – direct route from a sensory neuron, to an interneuron, to an effector Figure 7.11a

Simple Reflex Arc Slide 7.24 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 7.11b, c

Types of Reflexes and Regulation Slide 7.25 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Autonomic reflexes  Smooth muscle regulation  Heart and blood pressure regulation  Regulation of glands  Digestive system regulation  Somatic reflexes  Activation of skeletal muscles

Cranial and Spinal Nerves Part of the peripheral nervous system 12 pairs of cranial nerves 31 pairs of spinal nerves –Direct connection –Plexus

Sensory and Motor Areas of the Cerebral Cortex Slide 7.31 Figure 7.14

Cranial Nerves I –Olfactory II –Optic III –Oculomotor IV –Trochlear Edited by Dr. Ryan Lambert-Bellacov

Cranial Nerves V –Trigeminal VI –Abducens VII –Facial VIII –Vestibulocochlear Edited by Dr. Ryan Lambert-Bellacov

Cranial Nerves IX –Glossopharyngeal X –Vagus XI –Spinal accessory XII –Hypoglossal Edited by Dr. Ryan Lambert-Bellacov

Spinal Nerve Plexus Cervical plexus Brachial plexus Lumbar plexus Sacral plexus Edited by Dr. Ryan Lambert-Bellacov

Autonomic Nervous System Nerves, ganglia, and plexuses which carry impulses to all smooth muscle, secretory glands, and heart muscle Sympathetic system Parasympathetic system Strongly influenced by emotion

Sympathetic System Consists primarily of two cords, beginning at the base of the brain and proceeding down both sides of the spinal column Fight or flight system

Sympathetic System Learning to cope with stress is essential to preventing over stimulation of this system and the subsequent problems –It was meant for acute stress, not chronic stress

Parasympathetic System Vagus nerve Pelvic nerves Counteracts effects of the sympathetic nervous system

Biofeedback Measurement of physiological responses Yields information about the relationships between the mind and the body Can learn to manipulate these responses through mental activity

Types of Anesthesia Local numbing of area Regional anesthesia –Spinal anesthesia –Epidural anesthesia –Nerve blocks General anesthesia

Disorders Neuritis Peripheral neuropathy Sciatica Edited by Dr. Ryan Lambert-Bellacov

Disorders Trigeminal neuralgia Bell’s palsy Shingles or herpes zoster Carpal tunnel syndrome Edited by Dr. Ryan Lambert-Bellacov

Specialized Area of the Cerebrum Slide 7.32a  Cerebral areas involved in special senses  Gustatory area (taste)  Visual area  Auditory area  Olfactory area Edited by Dr. Ryan Lambert-Bellacov