ELAINE N. MARIEB EIGHTH EDITION 7 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings PowerPoint ® Lecture Slide Presentation by Jerry L. Cook, Sam Houston University ESSENTIALS OF HUMAN ANATOMY & PHYSIOLOGY PART A The Nervous System

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Functions of the Nervous System  _________ input – gathering information  To monitor changes occurring inside and outside the body  Changes = _________  ____________  To process and interpret sensory input and decide if action is needed

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Functions of the Nervous System  _________ output  A response to integrated stimuli  The response activates_________ or _________

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Structural Classification of the Nervous System  Central nervous system (CNS)  ________  ________ ______  Peripheral nervous system (PNS)  _________ outside the brain and spinal cord

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Figure 7.1 Functional Classification of the Peripheral Nervous System  Sensory (_________) division  Nerve fibers that _________________ the ___________ nervous system

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Figure 7.1 Functional Classification of the Peripheral Nervous System  Motor (_________) division  Nerve fibers that _______________ _____________central nervous system

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Figure 7.1 Functional Classification of the Peripheral Nervous System  Motor (efferent) division  Two subdivisions  ________________ system = _________  ____________ nervous system = _________

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Organization of the Nervous System Figure 7.2

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Figure 7.3a Nervous Tissue: Support Cells (Neuroglia)  Astrocytes  Abundant, star-shaped cells  Brace neurons  Form barrier between capillaries and neurons  Control the chemical environment of the brain

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Nervous Tissue: Support Cells  Microglia  Spider-like phagocytes  Dispose of debris  Ependymal cells  Line cavities of the brain and spinal cord  Circulate cerebrospinal fluid Figure 7.3b–c

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Nervous Tissue: Support Cells  Oligodendrocytes  Produce myelin sheath around nerve fibers in the central nervous system Figure 7.3d

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Figure 7.3e Nervous Tissue: Support Cells  Satellite cells  Protect neuron cell bodies  Schwann cells  Form myelin sheath in the peripheral nervous system

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Nervous Tissue: Neurons  Neurons = _________ _____  Cells specialized to transmit messages  Major regions of neurons  _________ – nucleus and metabolic center of the cell  ___________ – fibers that extend from the cell body

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Neuron Anatomy  Cell body  _________  Large __________ Figure 7.4a–b

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Neuron Anatomy  Extensions outside the cell body  ________ – conduct impulses ______ the cell body  _______ – conduct impulses ______ ______ the cell body Figure 7.4a

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Axons and Nerve Impulses  Axons end in axonal terminals  Axonal terminals contain vesicles with neurotransmitters  Axonal terminals are separated from the next neuron by a gap  ____________ ______– gap between adjacent neurons  __________ – junction between nerves

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Nerve Fiber Coverings  Schwann cells – produce ___________ _____________ __like fashion  Nodes of Ranvier – ______ in myelin sheath along the axon Figure 7.5

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Neuron Cell Body Location  Most are found in the central nervous system  Gray matter – _______ ______ and ___________ fibers  Nuclei – clusters of cell bodies within the white matter of the central nervous system  __________ – collections of cell bodies ________ the central nervous system

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Functional Classification of Neurons  ________ (afferent) neurons  Carry impulses from the sensory receptors  Cutaneous sense organs  Proprioceptors – detect stretch or tension  ________ (efferent) neurons  Carry impulses from the central nervous system

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Functional Classification of Neurons  ___________ (association neurons)  Found in neural pathways in the central nervous system  Connect sensory and motor neurons

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Neuron Classification Figure 7.6

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Structural Classification of Neurons  Multipolar neurons – many extensions from the cell body Figure 7.8a

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Structural Classification of Neurons  Bipolar neurons – one axon and one dendrite Figure 7.8b

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Structural Classification of Neurons  Unipolar neurons – have a short single process leaving the cell body Figure 7.8c

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Functional Properties of Neurons  ____________ – ability to respond to stimuli  ____________ – ability to transmit an impulse  The plasma membrane at rest is polarized  Fewer positive ions are inside the cell than outside the cell