Transcript Slide 1
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 Cell body Nucleus Large nucleolus Edited by Dr. Ryan Lambert-Bellacov Figure 7.4a Slide 7.9b Nerves • Bundles of nerve fibers enclosed by connective tissue – Sensory or afferent nerves – Motor or efferent nerves – Mixed nerves Neuron Classification Figure 7.6 Slide 7.15 Neuron Cell Body Location 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 Slide 7.13 How Neurons Function (Physiology) 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 Slide 7.17 Starting a Nerve Impulse 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 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 7.18 The Action Potential 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 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 7.19 Nerve Impulse Propagation The impulse continues to move toward the cell body Impulses travel faster when fibers have a myelin sheath Figure 7.9c–e Slide 7.20 How Neurons Communicate at Synapses Figure 7.10 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 7.22 The Reflex Arc 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 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 7.23 Simple Reflex Arc Figure 7.11b, c Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 7.24 Types of Reflexes and Regulation Autonomic reflexes Smooth muscle regulation Heart and blood pressure regulation Regulation of glands Digestive system regulation Somatic reflexes Activation of skeletal muscles Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 7.25 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 Figure 7.14 Slide 7.31 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 Cerebral areas involved in special senses Gustatory area (taste) Visual area Auditory area Olfactory area Edited by Dr. Ryan Lambert-Bellacov Slide