Warm-Up Name as many structures of the nervous system as you can What do you think the major functions of the nervous system are? Name one other body system and how you think it works with the nervous system

The Nervous System: An Overview Ch. 7a

Functions of the Nervous System Sensory input – gathering information To monitor changes occurring inside and outside the body Changes = stimuli Integration To process and interpret sensory input and decide if action is needed Motor output A response to integrated stimuli The response activates muscles or glands Slide 7.1a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Quick Quiz 1 of 5 What are the 3 major functions of the Nervous system? Give an example of the nervous system performing these functions

Structural Classification of the Nervous System Central nervous system (CNS) Brain Spinal cord Peripheral nervous system (PNS) Nerves outside the brain and spinal cord Slide 7.2 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Quick Quiz 2 of 5 What organs make up the Central Nervous System? Which do you think would have a greater negative effect on the body and WHY?: Damaging the CNS, or Damaging the PNS

Some important terms… Afferent Efferent Toward the Body (spinal cord and brain) Often called “sensory” Efferent Away from the body (spinal cord and brain) Often called “motor”

Functional Classification of the Peripheral Nervous System Sensory (afferent) division Nerve fibers that carry information to the central nervous system Figure 7.1 Slide 7.3a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Functional Classification of the Peripheral Nervous System Motor (efferent) division Nerve fibers that carry impulses away from the central nervous system Two subdivisions Somatic nervous system = voluntary Autonomic nervous system = involuntary Figure 7.1 Slide 7.3b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Functional Classification of the Peripheral Nervous System Figure 7.1 Slide 7.3c Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Quick Quiz 3 of 5 What is the function of the Afferent Nervous System? Give an example What is the function of the Efferent Nervous system?

Organization of the Nervous System Figure 7.2 Slide 7.4 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

What makes up the nervous system? Nervous Tissue made of: Neurons Cells of the nervous system that transmit messages throughout the body Neuroglia Non-neural tissue of the nervous system Provides support

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 Slide 7.5 Copyright © 2003 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 Slide 7.6 Copyright © 2003 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 Slide 7.7a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Nervous Tissue: Support Cells Satellite cells Protect neuron cell bodies Schwann cells Form myelin sheath in the peripheral nervous system Figure 7.3e Slide 7.7b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Quick Quiz 4 of 5 What is the difference between Schwann Cells and Oligodendrocytes?

Nervous Tissue: Neurons 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 Slide 7.8 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Neuron Anatomy Cell body Nissl substance – specialized rough endoplasmic reticulum Neurofibrils – intermediate cytoskeleton that maintains cell shape Figure 7.4a Slide 7.9a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Neuron Anatomy Cell body Nucleus Large nucleolus Figure 7.4a Slide 7.9b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Neuron Anatomy Extensions outside the cell body Dendrites conduct impulses toward the cell body Receivers Axons conduct impulses away from the cell body Senders Figure 7.4a Slide 7.10

Get out notes from Tuesday What is the function of the Dendrites? How does a nerve impulse travel from one neuron to the next?

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 Slide 7.12 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Axons and Nerve Impulses Axons end in axonal terminals Axonal terminals release vesicles with neurotransmitters Axonal terminals are separated from the next neuron by a gap Synaptic cleft gap between adjacent neurons Synapse junction between nerves Slide 7.11 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings