Transcript 7A Nervous System

7
The Nervous System
PART A
PowerPoint® Lecture Slide Presentation by Jerry L. Cook, Sam Houston University
ESSENTIALS
OF HUMAN
ANATOMY
& PHYSIOLOGY
EIGHTH EDITION
ELAINE N. MARIEB
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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
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Functions of the Nervous System
 _________ output
 A response to integrated stimuli
 The response activates_________ or
_________
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Structural Classification of the Nervous
System
 Central nervous system (CNS)
 ________
 ________ ______
 Peripheral nervous system (PNS)
 _________ outside the brain and spinal
cord
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Functional Classification of the Peripheral
Nervous System
 Sensory (_________) division
 Nerve fibers that _________________ the
___________ nervous system
Figure 7.1
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Functional Classification of the Peripheral
Nervous System
 Motor (_________) division
 Nerve fibers that _______________
_____________central nervous system
Figure 7.1
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Functional Classification of the Peripheral
Nervous System
 Motor (efferent) division
 Two subdivisions
 ________________ system = _________
 ____________ nervous system = _________
Figure 7.1
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Organization of the Nervous System
Figure 7.2
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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
Figure 7.3a
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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
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Nervous Tissue: Support Cells
 Oligodendrocytes
 Produce myelin sheath around nerve fibers
in the central nervous system
Figure 7.3d
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Nervous Tissue: Support Cells
 Satellite cells
 Protect neuron cell bodies
 Schwann cells
 Form myelin sheath in the peripheral
nervous system
Figure 7.3e
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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
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Neuron Anatomy
 Cell body
 _________
 Large __________
Figure 7.4a–b
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Neuron Anatomy
 Extensions outside
the cell body
 ________ –
conduct impulses
______ the cell
body
 _______ –
conduct impulses
______ ______
the cell body
Figure 7.4a
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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
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Nerve Fiber Coverings
 Schwann cells –
produce ___________
_____________
__like fashion
 Nodes of Ranvier –
______ in myelin
sheath along the axon
Figure 7.5
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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
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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
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Functional Classification of Neurons
 ___________ (association neurons)
 Found in neural pathways in the central
nervous system
 Connect sensory and motor neurons
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Neuron Classification
Figure 7.6
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Structural Classification of Neurons
 Multipolar neurons – many extensions from
the cell body
Figure 7.8a
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Structural Classification of Neurons
 Bipolar neurons – one axon and one dendrite
Figure 7.8b
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Structural Classification of Neurons
 Unipolar neurons – have a short single
process leaving the cell body
Figure 7.8c
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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
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