Efnisyfirlit

• Cover image
• Title page
• Table of Contents
• How to use
• Copyright
• Preface
• Acknowledgments
• SECTION ONE. Fundamental Physicochemical Concepts
• 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
• Bibliography
• 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 examining 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
• Bibliography
• 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 volume changes
• Osmotic pressure drives the net transport of water during osmosis
• Only impermeant solutes can have persistent osmotic effects
• Summary
• Key words and concepts
• Study problems
• Bibliography
• 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
• Bibliography
• SECTION TWO. Ion Channels and Excitable Membranes
• 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
• Bibliography
• 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 membrane can be represented by an electrical equivalent circuit with a resistor and a capacitor in parallel
• 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
• Bibliography
• 7.  Generation and propagation of the action potential
• The action potential is a rapid and transient depolarization of the membrane 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
• Bibliography
• 8.  Ion channel diversity
• Various types of ion channels help 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
• Bibliography
• SECTION THREE. Solute Transport
• 9.  Electrochemical potential energy and transport processes
• Electrochemical potential energy drives all transport processes
• Summary
• Key words and concepts
• Study problems
• Bibliography
• 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 transport of one solute to “downhill” transport of another solute enables carriers to move the cotransported or countertransported solute “uphill” against an electrochemical gradient
• Na+ is cotransported with a variety of solutes such as glucose and amino acids
• 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
• Bibliography
• 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
• Bibliography
• SECTION FOUR. Physiology of Synaptic Transmission
• 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
• Bibliography
• 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
• Bibliography
• SECTION FIVE. Physiology of Muscle Contraction
• 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
• Bibliography
• 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 muscle
• Smooth muscle excitation-contraction coupling is fundamentally different from that in skeletal and cardiac muscles
• Summary
• Key words and concepts
• Study problems
• Bibliography
• 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 are complex
• Summary
• Key words and concepts
• Study problems
• Bibliography
• Epilogue
• Appendix A Abbreviations, symbols, and numerical constants
• Appendix B A mathematical refresher
• Appendix C Root-mean-squared displacement of diffusing molecules
• Appendix D Summary of elementary circuit theory
• Appendix E Answers to study problems
• Appendix F Comprehensive review examination
• Index