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PowerPoint Presentation for Biopsychology, 8th Edition by John P.J. Pinel Prepared by Jeffrey W. Grimm Western Washington University Copyright © 2011 Pearson Education, Inc. All rights reserved. This multimedia product and its contents are protected under copyright law. The following are prohibited by law: • any public performance or display, including transmission of any image over a network; • preparation of any derivative work, including the extraction, in whole or in part, of any images; • any rental, lease, or lending of the program. Chapter 3 The Anatomy of the Nervous System Systems, Structures, and Cells That Make Up Your Nervous System Copyright © 2011 Pearson Education, Inc. All rights reserved. General Layout of the Nervous System Central Nervous System (CNS) Brain (in the skull) Spinal Cord (in the spine) Peripheral Nervous System (PNS) Located outside of the skull and spine Serves to bring information into the CNS and carry signals out of the CNS Copyright © 2011 Pearson Education, Inc. All rights reserved. General Layout of the Nervous System Continued Peripheral Nervous System Somatic Nervous System Afferent nerves (sensory) Efferent nerves (motor) Autonomic Nervous System Sympathetic and parasympathetic nerves Both are efferent Copyright © 2011 Pearson Education, Inc. All rights reserved. Autonomic Nervous System All nerves are efferent Sympathetic and parasympathetic nerves generally have opposite effects Two-stage neural paths, neuron exiting the CNS synapses on a second-stage neuron before the target organ Copyright © 2011 Pearson Education, Inc. All rights reserved. Autonomic Nervous System Continued Sympathetic Thoracic and lumbar “Fight or flight” Second stage neurons are far from the target organ Parasympathetic Cranial and sacral “Rest and restore” Second stage neurons are near the target organ Copyright © 2011 Pearson Education, Inc. All rights reserved. FIGURE 3.2 The major divisions of the nervous system. Copyright © 2011 Pearson Education, Inc. All rights reserved. Meninges, Ventricles, and Cerebrospinal Fluid (CSF) CNS encased in bone and covered by three meninges Dura mater – tough outer membrane Arachnoid membrane – web-like Pia mater – adheres to CNS surface Cerebrospinal fluid (CSF) Fluid serves as cushion Copyright © 2011 Pearson Education, Inc. All rights reserved. FIGURE 3.3 The cerebral ventricles. Copyright © 2011 Pearson Education, Inc. All rights reserved. Protecting the Brain Chemical protection The blood-brain barrier – tightly-packed cells of blood vessel walls prevent entry of many molecules Physical protection Skull Meninges Cerebrospinal fluid (CSF) Copyright © 2011 Pearson Education, Inc. All rights reserved. Cells of the Nervous System: Anatomy of Neurons Neurons Specialized cells for the reception, conduction, and transmission of electrochemical signals Many sizes and shapes Copyright © 2011 Pearson Education, Inc. All rights reserved. FIGURE 3.5 The major external features of a typical neuron. Copyright © 2011 Pearson Education, Inc. All rights reserved. FIGURE 3.6 The major internal features of a typical neuron. Copyright © 2011 Pearson Education, Inc. All rights reserved. FIGURE 3.7 The cell membrane is a lipid bilayer with signal proteins and channel proteins embedded in it. Copyright © 2011 Pearson Education, Inc. All rights reserved. FIGURE 3.8 A unipolar neuron, a bipolar neuron, a multipolar neuron, and an interneuron. Copyright © 2011 Pearson Education, Inc. All rights reserved. Glial Cells: The Forgotten Cells Glial cells Outnumber neurons 10:1 Support neurons Recent evidence for glial communication and modulatory effects of glia on neuronal communication Four classes of Glial cells: Oligodendrocytes – extensions rich in myelin create myelin sheaths in CNS Schwann cells – similar to function of oligodendrocytes but in PNS, can guide axonal regeneration Astrocytes – largest glia, star-shaped, many functions Microglia – involved in response to injury or disease Copyright © 2011 Pearson Education, Inc. All rights reserved. FIGURE 3.9 The myelination of CNS axons by an oligodendrocyte and the myelination of PNS axons by Schwann cells. Copyright © 2011 Pearson Education, Inc. All rights reserved. Terminology Note CNS PNS Myelin-providing glia Oligodendrocytes Schwann cells Clusters of cell bodies Nuclei (singular nucleus) Ganglia (singular ganglion) Bundles of axons Tracts Nerves Copyright © 2011 Pearson Education, Inc. All rights reserved. Neuroanatomical Techniques and Directions Golgi stain – allows for visualization of individual neurons Nissl stain – selectively stains cell bodies Electron microscopy – provides information about the details of neuronal structure Copyright © 2011 Pearson Education, Inc. All rights reserved. FIGURE 3.11 Neural tissue that has been stained by the Golgi method. (Ed Reschke © Peter Arnold, Inc.) Copyright © 2011 Pearson Education, Inc. All rights reserved. FIGURE 3.12 The Nissl stain. (Courtesy of Carl Ernst and Brian Christie, Department of Psychology, University of British Columbia.) Copyright © 2011 Pearson Education, Inc. All rights reserved. FIGURE 3.13 A color-enhanced scanning electron micrograph of a neuron cell body (green) studded with terminal buttons (orange). Courtesy of Jerold J. M. Chun, M.D., Ph.D. Copyright © 2011 Pearson Education, Inc. All rights reserved. Neuroanatomical Tracing Techniques Anterograde (forward) tracing to where axons project away from an area Retrograde (backward) tracing from where axons are projecting into an area Copyright © 2011 Pearson Education, Inc. All rights reserved. FIGURE 3.14 Anatomical directions in a representative vertebrate (cat). Copyright © 2011 Pearson Education, Inc. All rights reserved. FIGURE 3.15 Anatomical directions in a human. Copyright © 2011 Pearson Education, Inc. All rights reserved. Directions in the Vertebrate Nervous System Continued Anatomical directions ignore the fact that humans walk upright. Therefore, top of the head is both “dorsal” (back) and “superior” (top) Other directions: Medial – toward the middle Lateral – toward the side Proximal – close Distal – far Copyright © 2011 Pearson Education, Inc. All rights reserved. Sections of the Brain Horizontal – a slice parallel to the ground Frontal (coronal) – slicing bread or salami Sagittal – a midsagittal section separates the left and right halves Copyright © 2011 Pearson Education, Inc. All rights reserved. FIGURE 3.16 Horizontal, frontal (coronal), and sagittal planes in the human brain and a cross section of the human spinal cord. Copyright © 2011 Pearson Education, Inc. All rights reserved. Spinal Cord Gray matter – inner component, primarily cell bodies White matter – outer area, mainly myelinated axons Dorsal – afferent, sensory Ventral – efferent, motor Copyright © 2011 Pearson Education, Inc. All rights reserved. FIGURE 3.17 The dorsal and ventral roots of the spinal cord. FIGURE 3.18 A schematic cross section of the spinal cord. Copyright © 2011 Pearson Education, Inc. All rights reserved. FIGURE 3.19 The early development of the mammalian brain illustrated in schematic horizontal sections. Copyright © 2011 Pearson Education, Inc. All rights reserved. FIGURE 3.20 The divisions of the adult human brain. Copyright © 2011 Pearson Education, Inc. All rights reserved. Major Structures of the Brain Myelencephalon = medulla Composed largely of tracts Origin of the reticular formation Metencephalon Many tracts Pons – ventral surface Cerebellum – coordination Copyright © 2011 Pearson Education, Inc. All rights reserved. FIGURE 3.21 Structures of the human myelencephalon (medulla) and metencephalon. Copyright © 2011 Pearson Education, Inc. All rights reserved. Major Structures of the Brain Continued Mesencephalon = midbrain tectum has inferior and superior colliculi tegmentum has periaqueductal gray, substantia nigra, and red nucleus Diencephalon thalamus hypothalamus Copyright © 2011 Pearson Education, Inc. All rights reserved. FIGURE 3.22 The human mesencephalon (midbrain). Copyright © 2011 Pearson Education, Inc. All rights reserved. FIGURE 3.23 The human diencephalon. Copyright © 2011 Pearson Education, Inc. All rights reserved. Telencephalon – Cerebral Cortex Convolutions serve to increase surface area Longitudinal fissure – a groove that separates right and left hemispheres Corpus callosum – largest hemisphere-connecting tract Copyright © 2011 Pearson Education, Inc. All rights reserved. FIGURE 3.25 The major fissures of the human cerebral cortex. FIGURE 3.26 The lobes of the cerebral hemishphere. Copyright © 2011 Pearson Education, Inc. All rights reserved. Telencephalon – Subcortical Structures Limbic system – regulation of motivated behaviors Mammillary bodies, hippocampus, amygdala, fornix, cingulate, septum Basal ganglia motor system Amygdala, striatum (caudate nucleus + putamen), globus pallidus Copyright © 2011 Pearson Education, Inc. All rights reserved. FIGURE 3.28 The major structures of the limbic system: amygdala, hippocampus, cingulate cortex, fornix, septum, and mammillary body. Copyright © 2011 Pearson Education, Inc. All rights reserved. FIGURE 3.29 The basal ganglia: amygdala, striatum (caudate plus putamen) and globus pallidus. Copyright © 2011 Pearson Education, Inc. All rights reserved. FIGURE 3.30 Summary of major brain structures. Copyright © 2011 Pearson Education, Inc. All rights reserved.