Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Fundamentals of Anatomy & Physiology SIXTH EDITION Frederic H. Martini PowerPoint ® Lecture Slide Presentation prepared by Dr. Kathleen A. Ireland, Biology Instructor, Seabury Hall, Maui, Hawaii Chapter 15, part 1 Neural Integration I: Sensory Pathways and the Somatic Nervous System
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Learning Objectives Specify the components of the afferent and efferent divisions of the nervous system, and explain what is meant by the somatic nervous system. Explain why receptors respond to specific stimuli and how the organization of a receptor affects its sensitivity. Identify the major sensory pathways.
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Learning Objectives Explain how we can distinguish among sensations that originate in different areas of the body. Describe the components, processes and functions of the somatic motor pathways. Describe the levels of information processing involved in motor control.
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings SECTION 15-1 An Overview of Sensory Pathways and the Somatic Nervous System
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Neural pathways Afferent pathways Sensory information coming from the sensory receptors through peripheral nerves to the spinal cord and on to the brain Efferent pathways Motor commands coming from the brain and spinal cord, through peripheral nerves to effecter organs
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 15.1 An Overview of Neural Integration Figure 15.1
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings SECTION 15-2 Sensory Receptors and their Classification
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Specialized cell or cell process that monitors specific conditions Arriving information is a sensation Awareness of a sensation is a perception Sensory receptor
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings General senses Pain Temperature Physical distortion Chemical detection Receptors for general senses scattered throughout the body Special senses Located in specific sense organs Structurally complex Senses
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Each receptor cell monitors a specific receptive field Transduction A large enough stimulus changes the receptor potential, reaching generator potential Sensory receptors
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Tonic receptors Always active Slow acting receptors Phasic receptors Provide information about the intensity and rate of change of a stimulus Fast acting receptors Adaptation Reduction in sensitivity in the presence of a constant stimulus Receptors
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Three types of nociceptor Provide information on pain as related to extremes of temperature Provide information on pain as related to extremes of mechanical damage Provide information on pain as related to extremes of dissolved chemicals Myelinated type A fibers carry fast pain Slower type C fibers carry slow pain The general senses
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 15.2 Figure 15.2 Receptors and Receptive Fields
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Found in the dermis Mechaniceptors Sensitive to distortion of their membrane Tactile receptors (six types) Baroreceptors Proprioceptors (three groups) Thermoceptors and mechaniceptors
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 15.3 Tactile Receptors in the Skin Figure 15.3a-f
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Chemoreceptors Carotid bodies Aortic bodies Chemoreceptors
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 15.4 Figure 15.4 Baroreceptors and the Regulation of Visceral Function
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 15.5 Figure 15.5 Chemoreceptors