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 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings

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. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings

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 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings

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 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings

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 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings

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 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings

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

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