Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Dee Unglaub Silverthorn, Ph.D. H UMAN P HYSIOLOGY PowerPoint ® Lecture Slide Presentation by Dr. Howard D. Booth, Professor of Biology, Eastern Michigan University AN INTEGRATED APPROACH T H I R D E D I T I O N Chapter 6, part A Communication, Integration, and Homeostasis

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings About this Chapter How cells communicate Electrical and chemical signals Receptor types and how they function Local regulation of cells Modification of receptors and signals Homeostatic balance depends on communication Feedback regulates integration of systems

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Chemical Autocrine & Paracrine: local signaling Endocrine system: distant, diffuse target Electrical Gap junction: local Nervous system: fast, specific, distant target Overview of Cell to Cell Communication:

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Gap Junctions and CAMs Protein channels - connexin Direct flow to neighbor Electrical- ions (charge) Signal chemicals CAMs Need direct surface contact Signal chemical Figure 6-1a, b: Direct and local cell-to-cell communication

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Paracrines and Autocrines Local communication Signal chemicals diffuse to target Example: Cytokines Autocrine–receptor on same cell Paracrine– neighboring cells Figure 6-1c: Direct and local cell-to-cell communication

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Signal Chemicals Made in endocrine cells Transported via blood Receptors on target cells Long Distance Communication: Hormones Figure 6-2a: Long distance cell-to-cell communication

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Neurons Electrical signal down axon Signal molecule (neurotransmitter) to target cell Neurohormones Chemical and electrical signals down axon Hormone transported via blood to target Long Distance Communication: Neurons and Neurohormones Figure 6-2 b: Long distance cell-to-cell communication

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Long Distance Communication: Neurons and Neurohormones Figure 6-2b, c: Long distance cell-to-cell communication

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Signal Pathways Signal molecule (ligand) Receptor Intracellular signal Target protein Response Figure 6-3: Signal pathways

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Receptor locations Cytosolic or Nuclear Lipophilic ligand enters cell Often activates gene Slower response Cell membrane Lipophobic ligand can't enter cell Outer surface receptor Fast response Figure 6-4: Target cell receptors

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Ligand- gated channel Receptor enzymes G-protein-coupled Integrin Membrane Receptor Classes

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Membrane Receptor Classes Figure 6-5: Four classes of membrane receptors

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Signal Transduction Transforms signal energy Protein kinase Second messenger Activate proteins Phosporylation Bind calcium Cell response Figure 6-8: Biological signal transduction

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Signal Amplification Small signal produces large cell response Amplification enzyme Cascade Figure 6-7: Signal amplification

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Receptor Enzymes Transduction Activation cytoplasmic Side enzyme Example: Tyrosine kinase Figure 6-10: Tyrosine kinase, an example of a receptor-enzyme

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings G-Protein-coupled Receptors Hundreds of types Main signal transducers Activate enzymes Open ion channels Amplify: adenyl cyclase-cAMP Activates synthesis

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings G-Protein-coupled Receptors Figure 6-11: The G protein-coupled adenylyl cyclase-cAMP system

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Transduction Reviewed Figure 6-14: Summary of signal transduction systems

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Novel Signal Molecules Calcium: muscle contraction Channel opening Enzyme activation Vesicle excytosisNitric Oxide (NO) Paracrine: arterioles Activates cAMP Brain neurotransmitter Carbon monoxide (CO)

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Novel Signal Molecules Figure 6-15: Calcium as an intracellular messenger