SECTION I, Fundamental Physicochemical Concepts CHAPTER 1, INTRODUCTION: HOMEOSTASIS AND CELLULAR PHYSIOLOGY Homeostasis Enables the Body to Survive in Diverse Environments The Body Is an Ensemble of Functionally and Spatially Distinct Compartments Transport Processes Are Essential to Physiological Function Cellular Physiology Focuses on Membrane-Mediated Processes and on Muscle Function Summary Key Words and Concepts CHAPTER 2, DIFFUSION AND PERMEABILITY Diffusion Is the Migration of Molecules down a Concentration Gradient Fick's First Law of Diffusion Summarizes our Intuitive Understanding of Diffusion Essential Aspects of Diffusion Are Revealed by Quantitative Examination of Random, Microscopic Movements of Molecules Fick's First Law Can Be Used to Describe Diffusion across a Membrane Barrier Summary Key Words and Concepts Study Problems CHAPTER 3, OSMOTIC PRESSURE AND WATER MOVEMENT Osmosis Is the Transport of Solvent Driven by a Difference in Solute Concentration Across a Membrane That Is Impermeable to Solute Water Transport during Osmosis Leads to Changes in Volume Osmotic Pressure Drives the Net Transport of Water during Osmosis Osmotic Pressure and Hydrostatic Pressure Are Functionally Equivalent in Their Ability to Drive Water Movement Through a Membrane Only Impermeant Solutes Can Have Permanent Osmotic Effects Summary Key Words and Concepts Study Problems CHAPTER 4, ELECTRICAL CONSEQUENCES OF IONIC GRADIENTS Ions Are Typically Present at Different Concentrations on Opposite Sides of a Biomembrane Selective Ionic Permeability Through Membranes Has Electrical Consequences: The Nernst Equation The Stable Resting Membrane Potential in a Living Cell Is Established by Balancing Multiple Ionic Fluxes The Cell Can Change Its Membrane Potential by Selectively Changing Membrane Permeability to Certain Ions The Donnan Effect Is an Osmotic Threat to Living Cells Summary Key Words and Concepts Study Problems SECTION II, Ion Channels and Excitable Membranes CHAPTER 5, ION CHANNELS Ion Channels Are Critical Determinants of the Electrical Behavior of Membranes Distinct Types of Ion Channels Have Several Common Properties Ion Channels Share Structural Similarities and Can Be Grouped into Gene Families Summary Key Words and Concepts Study Problems CHAPTER 6, PASSIVE ELECTRICAL PROPERTIES OF MEMBRANES The Time Course and Spread of Membrane Potential Changes Are Predicted by the Passive Electrical Properties of the Membrane The Equivalent Circuit of a Membrane Has a Resistor in Parallel with a Capacitor Passive Membrane Properties Produce Linear Current-Voltage Relationships Membrane Capacitance Affects the Time Course of Voltage Changes Membrane and Axoplasmic Resistances Affect the Passive Spread of Subthreshold Electrical Signals Summary Key Words and Concepts Study Problems CHAPTER 7, GENERATION AND PROPAGATION OF THE ACTION POTENTIAL The Action Potential Is a Rapid and Transient Depolarization of the Membrane Potential in Electrically Excitable Cells Ion Channel Function Is Studied with a Voltage Clamp Individual Ion Channels Have Two Conductance Levels Na+ Channels Inactivate during Maintained Depolarization Action Potentials Are Generated by Voltage-Gated Na+ and K+ Channels Action Potential Propagation Occurs as a Result of Local Circuit Currents Summary Key Words and Concepts Study Problems CHAPTER 8, ION CHANNEL DIVERSITY Various Types of Ion Channels Help to Regulate Cellular Processes Voltage-Gated Ca2+ Channels Contribute to Electrical Activity and Mediate Ca2+ Entry into Cells Many Members of the Transient Receptor Potential Superfamily of Channels Mediate Ca2+ Entry K+-Selective Channels Are the Most Diverse Type of Channel Ion Channel Activity Can Be Regulated by Second-Messenger Pathways Summary Key Words and Concepts Study Problems SECTION III, Solute Transport CHAPTER 9, ELECTROCHEMICAL POTENTIAL ENERGY AND TRANSPORT PROCESSES Electrochemical Potential Energy Drives All Transport Processes Summary Key Words and Concepts Study Problems CHAPTER 10, PASSIVE SOLUTE TRANSPORT Diffusion across Biological Membranes Is Limited by Lipid Solubility Channel, Carrier, and Pump Proteins Mediate Transport across Biological Membranes Carriers Are Integral Membrane Proteins That Open to Only One Side of the Membrane at a Time Coupling the Transport of One Solute to the "Downhill" Transport of Another Solute Enables Carriers to Move the Cotransported or Countertransported Solute "Uphill" against an Electrochemical Gradient Net Transport of Some Solutes across Epithelia Is Effected by Coupling Two Transport Processes in Series Na+ Is Exchanged for Solutes Such as Ca2+ and H+ by Countertransport Mechanisms Multiple Transport Systems Can Be Functionally Coupled Summary Key Words and Concepts Study Problems CHAPTER 11, ACTIVE TRANSPORT Primary Active Transport Converts the Chemical Energy from ATP into Electrochemical Potential Energy Stored in Solute Gradients The Plasma Membrane Na+ Pump (Na+, K+-ATPase) Maintains the Low Na+ and High K+ Concentrations in the Cytosol Intracellular Ca2+ Signaling Is Universal and Is Closely Tied to Ca2+ Homeostasis Several Other Plasma Membrane Transport ATPases Are Physiologically Important Net Transport across Epithelial Cells Depends on the Coupling of Apical and Basolateral Membrane Transport Systems Summary Key Words and Concepts Study Problems SECTION IV, Physiology of Synaptic Transmission CHAPTER 12, SYNAPTIC PHYSIOLOGY I The Synapse Is a Junction Between Cells That Is Specialized for Cell-Cell Signaling Neurons Communicate with Other Neurons and with Muscle by Releasing Neurotransmitters The Synaptic Vesicle Cycle Is a Precisely Choreographed Process for Delivering Neurotransmitter into the Synaptic Cleft Short-Term Synaptic Plasticity Is a Transient, Use-Dependent Change in the Efficacy of Synaptic Transmission Summary Key Words and Concepts Study Problems CHAPTER 13, SYNAPTIC PHYSIOLOGY II Chemical Synapses Afford Specificity, Variety, and Fine Tuning of Neurotransmission Receptors Mediate the Actions of Neurotransmitters in Postsynaptic Cells Acetylcholine Receptors Can Be Ionotropic or Metabotropic Amino Acid Neurotransmitters Mediate Many Excitatory and Inhibitory Responses in the Brain Neurotransmitters That Bind to Ionotropic Receptors Cause Membrane Conductance Changes Biogenic Amines, Purines, and Neuropeptides Are Important Classes of Transmitters with a Wide Spectrum of Actions Unconventional Neurotransmitters Modulate Many Complex Physiological Responses Long-Term Synaptic Potentiation and Depression Are Persistent Changes in the Efficacy of Synaptic Transmission Induced by Neural Activity Summary Key Words and Concepts Study Problems SECTION V, Molecular Motors and Muscle Contraction CHAPTER 14, MOLECULAR MOTORS AND THE MECHANISM OF MUSCLE CONTRACTION Molecular Motors Produce Movement by Converting Chemical Energy into Kinetic Energy Single Skeletal Muscle Fibers Are Composed of Many Myofibrils The Sarcomere Is the Basic Unit of Contraction in Skeletal Muscle Muscle Contraction Results from Thick and Thin Filaments Sliding Past Each Other (The "Sliding Filament" Mechanism) The Cross-Bridge Cycle Powers Muscle Contraction In Skeletal and Cardiac Muscles, Ca2+ Activates Contraction by Binding to the Regulatory Protein Troponin C The Structure and Function of Cardiac Muscle and Smooth Muscle Are Distinctly Different from Those of Skeletal Muscle Summary Key Words and Concepts Study Problems CHAPTER 15, EXCITATION-CONTRACTION COUPLING IN MUSCLE Skeletal Muscle Contraction Is Initiated by a Depolarization of the Surface Membrane Direct Mechanical Interaction Between Sarcolemmal and Sarcoplasmic Reticulum Membrane Proteins Mediates Excitation-Contraction Coupling in Skeletal Muscle Ca2+-Induced Ca2+ Release Is Central to Excitation-Contraction Coupling in Cardiac MuscleSmooth Muscle Excitation-Contraction Coupling Is Fundamentally Different from That in Skeletal and Cardiac Muscles Summary Key Words and Concepts Study Problems CHAPTER 16, MECHANICS OF MUSCLE CONTRACTION The Total Force Generated by a Skeletal Muscle Can Be Varied Skeletal Muscle Mechanics Is Characterized by Two Fundamental Relationships There Are Three Types of Skeletal Muscle Motor Units The Force Generated by Cardiac Muscle Is Regulated by Mechanisms That Control Intracellular Ca2+ Mechanical Properties of Cardiac and Skeletal Muscle Are Similar but Quantitatively Different Dynamics of Smooth Muscle Contraction Differ Markedly from Those of Skeletal and Cardiac Muscle The Relationships among Intracellular Ca2+, Myosin Light Chain Phosphorylation, and Force in Smooth Muscles Is Complex Summary Key Words and Concepts Study Problems SEction VI Epilogue and Appendicies EPILOGUE APPENDIX A, ABBREVIATIONS, SYMBOLS, AND NUMERICAL CONSTANTS Abbreviations Symbols Numerical Constants APPENDIX B, A MATHEMATICAL REFRESHER Exponents Logarithms Solving Quadratic Equations Differentiation and Derivatives Integration: The Antiderivative and the Definite Integral Differential Equations APPENDIX C, ROOT-MEAN-SQUARED DISPLACEMENT OF DIFFUSING MOLECULES APPENDIX D, SUMMARY OF ELEMENTARY CIRCUIT THEORY Cell Membranes Are Modeled with Electrical Circuits Definitions of Electrical Parameters Current Flow in Simple Circuits APPENDIX E, ANSWERS TO STUDY PROBLEMS APPENDIX F, REVIEW EXAMINATION Answers to Review Examination
