Nervous Tissue Neurons nerve cells Cells specialized to

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Nervous Tissue: Neurons = nerve cells Cells specialized to transmit messages Major regions of

Nervous Tissue: Neurons = nerve cells Cells specialized to transmit messages Major regions of neurons Cell body – nucleus and metabolic center of the cell Processes – fibers that extend from the cell body Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 7. 8

Neuron Anatomy Cell body Nucleus Large nucleolus Figure 7. 4 a Copyright © 2003

Neuron Anatomy Cell body Nucleus Large nucleolus Figure 7. 4 a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 7. 9 b

Neuron Anatomy Extensions outside the cell body Dendrites – conduct impulses toward the cell

Neuron Anatomy Extensions outside the cell body Dendrites – conduct impulses toward the cell body Axons – conduct impulses away from the cell body Figure 7. 4 a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 7. 10

Axons and Nerve Impulses Axons end in axonal terminals Axonal terminals contain vesicles with

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 Synaptic cleft – gap between adjacent neurons Synapse – junction between nerves Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 7. 11

Nerve Fiber Coverings Schwann cells – produce myelin sheaths in jelly-roll like fashion Nodes

Nerve Fiber Coverings Schwann cells – produce myelin sheaths in jelly-roll like fashion Nodes of Ranvier – gaps in myelin sheath along the axon Figure 7. 5 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 7. 12

Nervous Tissue: Support Cells Schwann cells Form myelin sheath in the peripheral nervous system

Nervous Tissue: Support Cells Schwann cells Form myelin sheath in the peripheral nervous system Figure 7. 3 e Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 7. 7 b

Neuron Cell Body Location Most are found in the central nervous system Gray matter

Neuron Cell Body Location Most are found in the central nervous system Gray matter – cell bodies and unmylenated fibers Nuclei – clusters of cell bodies within the white matter of the central nervous system Ganglia – collections of cell bodies outside the central nervous system Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 7. 13

Functional Classification of Neurons Sensory (afferent) neurons Carry impulses from the sensory receptors Cutaneous

Functional Classification of Neurons Sensory (afferent) neurons Carry impulses from the sensory receptors Cutaneous sense organs Proprioceptors – detect stretch or tension Motor (efferent) neurons Carry impulses from the central nervous system Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 7. 14 a

Functional Classification of Neurons Interneurons (association neurons) Found in neural pathways in the central

Functional Classification of Neurons Interneurons (association neurons) Found in neural pathways in the central nervous system Connect sensory and motor neurons Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 7. 14 b

Neuron Classification Figure 7. 6 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin

Neuron Classification Figure 7. 6 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 7. 15

Structural Classification of Neurons Multipolar neurons – many extensions from the cell body Figure

Structural Classification of Neurons Multipolar neurons – many extensions from the cell body Figure 7. 8 a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 7. 16 a

Structural Classification of Neurons Bipolar neurons – one axon and one dendrite Figure 7.

Structural Classification of Neurons Bipolar neurons – one axon and one dendrite Figure 7. 8 b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 7. 16 b

Structural Classification of Neurons Unipolar neurons – have a short single process leaving the

Structural Classification of Neurons Unipolar neurons – have a short single process leaving the cell body Figure 7. 8 c Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 7. 16 c

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Specialized Cells Specialized Cells Specialized Does one thingSpecialized Cells Specialized Cells Specialized Does one thing
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Connective tissue Muscle tissue Nervous tissue Epithelial tissueConnective tissue Muscle tissue Nervous tissue Epithelial tissue
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THE NERVOUS SYSTEM Nerve Cells NERVE CELLS CalledTHE NERVOUS SYSTEM Nerve Cells NERVE CELLS Called
Neurons Synapses Signaling Neurons are nerve cells thatNeurons Synapses Signaling Neurons are nerve cells that
ANA 211 NERVE TISSUE INTRODUCTION Nerve tissue isANA 211 NERVE TISSUE INTRODUCTION Nerve tissue is
Chapter 2 Nerve Cells and Nerve Impulses NeuronsChapter 2 Nerve Cells and Nerve Impulses Neurons
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LECTURE NERVOUS TISSUE NERVE TERMINATIONS The nerve fiberLECTURE NERVOUS TISSUE NERVE TERMINATIONS The nerve fiber