Slide 7.1a Functions of the Nervous System Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  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

Slide 7.1b Functions of the Nervous System Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Motor output  A response to integrated stimuli  The response activates muscles or glands This ability to response quickly to environmental stimuli not restricted to animals

Evolution of nervous systems

Evolutionary trends Inter-neurons receive, store, and retrieve and integrate information: increased cognitive ability (intelligence). Increasing ability to modify responses based on past experiences Associated with ever increasing size of cerebrum and “plasticity” of network

Nerve network: eye Reconstruction of 114 rod bipolar nerve cells from a piece of mouse retina. The dendrites form dense bundles, where the bipolar cells receive signals from the photoreceptors.. (Photo Credit: MPI for Medical Research)

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

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

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

Slide 7.3c Functional Classification of the Peripheral Nervous System Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Motor (efferent) division  Two subdivisions  Somatic nervous system = voluntary  Autonomic nervous system = involuntary Figure 7.1

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