THIRD EDITION HUMAN PHYSIOLOGY AN INTEGRATED APPROACH Dee

THIRD EDITION HUMAN PHYSIOLOGY AN INTEGRATED APPROACH Dee Unglaub Silverthorn, Ph. D. Chapter 10, part A Sensory Physiology Power. Point® Lecture Slide Presentation by Dr. Howard D. Booth, Professor of Biology, Eastern Michigan University Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings

About this Chapter • What are the senses • How sensory systems work • Body sensors and homeostatic maintenance • Sensing the external environment • Mechanisms and pathways to perception Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings

General Properties of Sensory Systems • Stimulus • Internal • External • Energy source • Receptors • Sense organs • Transducer • Afferent pathway • CNS integration Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings

General Properties of Sensory Systems Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings Figure 10 -4: Sensory pathways

Sensory Receptor Types • Structural types: 1. Simple receptors 2. Complex neural 3. Special senses • Types according to the nature of stimulus 1. Chemoreceptors 2. Mechanoreceptors 3. Thermoreceptors 4. Photoreceptors Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings

Sensory Receptor Types Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings Figure 10 -1: Sensory receptors

Special Senses – External Stimuli • Vision • Hearing • Taste • Smell • Equilibrium Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings

Special Senses – External Stimuli Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings Figure 10 -4: Sensory pathways

Somatic Senses – Internal Stimuli • Touch • Temperature • Pain • Itch • Proprioception • Pathway Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings Figure 10 -10: The somatosensory cortex

Somatic Pathways • Receptor • Threshold • Action potential • Sensory neurons • Primary – medulla • Secondary – thalamus • Tertiary – cortex • Integration • Receptive field • Multiple levels Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings

Somatic Pathways Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings Figure 10 -9: Sensory pathways cross the body’s midline

Sensory Modality • Location • Lateral inhibition • Receptive field • Intensity • Duration • Tonic receptors • Phasic receptors • Adaptation Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings

Sensory Modality Figure 10 -3: Two-point discrimination Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings

Sensory Modality Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings Figure 10 -6: Lateral inhibition

Touch (pressure) • Mechanoreceptors • Free nerve endings • Pacinian corpuscles • Ruffini corpuscles • Merkel receptors • Meisaner's corpuscles • Barroreceptors Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings

Touch (pressure) Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings Figure 10 -11: Touch-pressure receptors

Temperature • Free nerve endings • Cold receptors • Warm receptors • Pain receptors • Sensory coding: • Intensity • Duration Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings

Temperature Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings Figure 10 -7: Sensory coding for stimulus intensity and duration

Pain and Itching • Nociceptors • Reflexive path • Itch • Fast pain • Slow pain Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings

Pain and Itching Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings Figure 10 -12: The gate control theory of pain modulation

Referred Pain Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings Figure 10 -13: Referred pain