Transcript 12-01_pptlect

Anatomy & Physiology
SIXTH EDITION
Chapter 12, part 1
Neural tissue
PowerPoint® Lecture Slide Presentation prepared by
Dr. Kathleen A. Ireland, Biology Instructor, Seabury Hall, Maui, Hawaii
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Frederic H. Martini
Fundamentals of
Learning Objectives
• Describe the two major divisions of the nervous
system and their characteristics.
• Identify the structures/functions of a typical
neuron.
• Describe the location and function of neuroglia.
• Explain how resting potential is created and
maintained.
• Describe the events in the generation and
propagation of an action potential.
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Learning Objectives
• Define the structure/function of a synapse.
• List the major types of neurotransmitters and
neuromodulators.
• Explain the processing of information in neural
tissue.
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SECTION 12-1
An Overview of the Nervous System
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nervous system overview
• Nervous system
• Provides swift, brief responses to stimuli
• Endocrine system
• Adjusts metabolic operations and directs longterm changes
• Nervous system includes
• All the neural tissue of the body
• Basic unit = neuron
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Divisions of the Nervous system
• CNS (Central Nervous system)
• Brain and spinal cord
• PNS (Peripheral Nervous system)
• Neural tissue outside CNS
• Afferent division brings sensory information
from receptors
• Efferent division carries motor commands to
effectors
• Efferent division includes somatic nervous
system and autonomic nervous system
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Figure 12.1 Functional Overview of the Nervous
System
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Figure 12.1
SECTION 12-2
Neurons
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Neuron structure
• Perikaryon
• Neurofilaments, neurotubules, neurofibrils
• Axon hillock
• Soma
• Axon
• Collaterals with telodendria
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Figure 12.2 The Anatomy of a Multipolar
Neuron
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Figure 12.2b
Synapse
• Site of intercellular communication
• Neurotransmitters released from synaptic knob
of presynaptic neuron
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Figure 12.3 The Structure of a Typical Synpase
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Figure 12.3
Neuron classification
• Anatomical
• Anaxonic
• Unipolar
• Bipolar
• Multipolar
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Figure 12.4 A Structural Classification of
Neurons
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Figure 12.4
Functional
• Sensory neurons
• deliver information from exteroceptors,
interoceptors, or proprioceptors
• Motor neurons
• Form the efferent division of the PNS
• Interneurons (association neurons)
• Located entirely within the CNS
• Distribute sensory input and coordinate
motor output
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Figure 12.5 A Functional Classification of
Neurons
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Figure 12.5
SECTION 12-3
Neuroglia
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Neuroglia of the Central Nervous System
• Four types of neuroglia in the CNS
• Ependymal cells
• Related to cerebrospinal fluid
• Astrocytes
• Largest and most numerous
• Oligodendrocytes
• Myelination of CNS axons
• Microglia
• Phagocytic cells
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Figure 12.6 An Introduction to Neuroglia
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Figure 12.6
Figure 12.7 Neuroglia in the CNS
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Figure 12.7a
Figure 12.7 Neuroglia in the CNS
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Figure 12.7b
Neuroglia of the Peripheral Nervous System
• Two types of neuroglia in the PNS
• Satellite cells
• Surround neuron cell bodies within ganglia
• Schwann cells
• Ensheath axons in the PNS
PLAY
Animation: Nervous system anatomy review
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings