lV CHAPTER 5 CHAPTER 7 Membrane potentials and action Excitation of skeletal muscle: Potentials 57 Neuromuscular Transmission and Basic Physics of Membrane Excitation-Contraction Coupling Membrane Potentials Caused by Diffusion Endings to Skeletal Muscle Fibers The Neuromuscular Junction Measuring the Membrane Potential Secretion of Acetylcholine by the Nerve Resting Membrane Potential of Nerves Terminals Origin of the Normal Resting Membrane Molecular Biology of Acetylin Formation and release Nerve Action potential Drugs That Enhance or Block Voltage-Gated Sodium and Potassium Transmission at the neuromuscular Junction the Events that cause the Myasthenia Gravis Action Potential Muscle Action potential Roles of other lons During the Action Spread of the Action Potential to the Initiation of the Action Potential Interior of the Muscle Fiber by Way “ Transverse tubu|es” Propagation of the Action Potential Re-establishing Sodium and Potassium Excitation-Contraction Coupling Transverse Tubule-Sarcoplasmic Reticulum lonic Gradients After Action potentials Are Completed-Importance of Energy Release of Calcium lons by the Metabolism Plateau in some action potentials Rhythmicity of Some Excitable Tissues Repetitive Dis ChAPtEr 8 pecial Characteristics of signal Contraction and Excitation of Transmission in Nerve Trunks 68 Smooth Muscle Excitation-The Process of Eliciting the Action potential Contraction of smooth muscle "Refractory Period"After an Action Types of Smooth Muscle Contractile mechanism in Smooth muscle Recording Membrane Potentials and Regulation of Contraction by Calcium lons Action Potentials Nervous and hormonal control of Inhibition of Excitability-Stabilizers Smooth Muscle Contraction and local anesthetics Neuromuscular junctions of smooth Muscle Membrane potentials and action potentials in Smooth muscle Effect of local tissue Factors and Hormones to cause smooth Muscle CHAPTER 6 Contraction Without Action Potentials Contraction of Skeletal Muscle Source of calcium lons that cause gic Anatomy of skeletal Contraction(/)Through the Cell Muscle Membrane and(2)from the Sarcoplasmic Skeletal Muscle Fiber Reticulum General Mechanism of muscle Contraction Molecular Mechanism of muscl U NITIII Contraction Molecular characteristics of the The heart Contractile Filaments Effect of Amount of Actin and Myosin CHAPTEr 9 lament Overlap on Tension Developed by the Contracting Muscle Heart Muscle; The Heart as a Pump Relation of velocity of Contraction to and Function of the heart Valves Load 78 Physiology of Cardiac Muscle Energetics of Muscle Contraction Physiologic Anatomy of Cardiac Muse 103 Work Output During Muscle Contraction 78 Action Potentials in Cardiac Muscle e Sources of Energy for Muscle Contraction The Cardiac Cycle Characteristics of whole muscle Diastole and syst Relationship of the Electrocardiogram to Mechanics of Skeletal Muscle Contraction the Cardiac Cycle Remodeling of Muscle to Match Function Function of the Atria as Primer Pumps Rigor Mortis Function of the Ventricles as Pumpsxiv Table of Contents CHAPTER 5 Membrane Potentials and Action Potentials 57 Basic Physics of Membrane Potentials 57 Membrane Potentials Caused by Diffusion 57 Measuring the Membrane Potential 58 Resting Membrane Potential of Nerves 59 Origin of the Normal Resting Membrane Potential 60 Nerve Action Potential 61 Voltage-Gated Sodium and Potassium Channels 62 Summary of the Events That Cause the Action Potential 64 Roles of Other Ions During the Action Potential 64 Initiation of the Action Potential 65 Propagation of the Action Potential 65 Re-establishing Sodium and Potassium Ionic Gradients After Action Potentials Are Completed—Importance of Energy Metabolism 66 Plateau in Some Action Potentials 66 Rhythmicity of Some Excitable Tissues— Repetitive Discharge 67 Special Characteristics of Signal Transmission in Nerve Trunks 68 Excitation—The Process of Eliciting the Action Potential 69 “Refractory Period” After an Action Potential 70 Recording Membrane Potentials and Action Potentials 70 Inhibition of Excitability—“Stabilizers” and Local Anesthetics 70 CHAPTER 6 Contraction of Skeletal Muscle 72 Physiologic Anatomy of Skeletal Muscle 72 Skeletal Muscle Fiber 72 General Mechanism of Muscle Contraction 74 Molecular Mechanism of Muscle Contraction 74 Molecular Characteristics of the Contractile Filaments 75 Effect of Amount of Actin and Myosin Filament Overlap on Tension Developed by the Contracting Muscle 77 Relation of Velocity of Contraction to Load 78 Energetics of Muscle Contraction 78 Work Output During Muscle Contraction 78 Sources of Energy for Muscle Contraction 79 Characteristics of Whole Muscle Contraction 80 Mechanics of Skeletal Muscle Contraction 81 Remodeling of Muscle to Match Function 82 Rigor Mortis 83 CHAPTER 7 Excitation of Skeletal Muscle: Neuromuscular Transmission and Excitation-Contraction Coupling 85 Transmission of Impulses from Nerve Endings to Skeletal Muscle Fibers: The Neuromuscular Junction 85 Secretion of Acetylcholine by the Nerve Terminals 85 Molecular Biology of Acetyline Formation and Release 88 Drugs That Enhance or Block Transmission at the Neuromuscular Junction 88 Myasthenia Gravis 89 Muscle Action Potential 89 Spread of the Action Potential to the Interior of the Muscle Fiber by Way of “Transverse Tubules” 89 Excitation-Contraction Coupling 89 Transverse Tubule–Sarcoplasmic Reticulum System 89 Release of Calcium Ions by the Sarcoplasmic Reticulum 90 CHAPTER 8 Contraction and Excitation of Smooth Muscle 92 Contraction of Smooth Muscle 92 Types of Smooth Muscle 92 Contractile Mechanism in Smooth Muscle 93 Regulation of Contraction by Calcium Ions 95 Nervous and Hormonal Control of Smooth Muscle Contraction 95 Neuromuscular Junctions of Smooth Muscle 95 Membrane Potentials and Action Potentials in Smooth Muscle 96 Effect of Local Tissue Factors and Hormones to Cause Smooth Muscle Contraction Without Action Potentials 98 Source of Calcium Ions That Cause Contraction (1) Through the Cell Membrane and (2) from the Sarcoplasmic Reticulum 99 UNIT III The Heart CHAPTER 9 Heart Muscle; The Heart as a Pump and Function of the Heart Valves 103 Physiology of Cardiac Muscle 103 Physiologic Anatomy of Cardiac Muscle 103 Action Potentials in Cardiac Muscle 104 The Cardiac Cycle 106 Diastole and Systole 106 Relationship of the Electrocardiogram to the Cardiac Cycle 107 Function of the Atria as Primer Pumps 107 Function of the Ventricles as Pumps 108