Quantitative Human Physiology

Quantitative Human Physiology: An Introduction, winner of a 2018 Textbook Excellence Award (Texty), is the first text to meet the needs of the undergraduate bioengineering student who is being exposed to physiology for the first time, but requires a more analytical/quantitative approach. This book explores how component behavior produces system behavior in physiological systems. Through text explanation, figures, and equations, it provides the engineering student with a basic understanding of physiological principles with an emphasis on quantitative aspects.

Table of Contents

• Preface
  • This Text Is a Physiology Text First, and Quantitative Second
  • The Text Uses Mathematics Extensively
  • Not All Things Worth Knowing Are Worth Knowing Well
  • Perfect Is the Enemy of Good: Equations Aren’t Perfect, but They’re Often Good Enough
  • Examples and Problem Sets Allow Application of the Useful Equations
  • Learning Objectives, Summaries, and Review Questions Guide Student Learning
  • Clinical Applications Pique Interest
  • How Instructors Can Use This Text
  • Ancillary Materials for Instructors
  • How students Can Use This Text
  • Ancillary Materials for Students
  • Student Feedback
• Acknowledgments
• Unit 1: Physical and Chemical Foundations of Physiology
  • 1. 1. The Core Principles of Physiology
    • Abstract
    • Human Physiology Is the Integrated Study of the Normal Function of the Human Body
    • The Body Consists of Causal Mechanisms That Obey the Laws of Physics and Chemistry
    • The Core Principles of Physiology
    • Cells Are the Organizational Unit of Life
    • The Concept of Homeostasis Is a Central Theme of Physiology
    • Evolution Is an Efficient Cause of the Human Body Working Over Longtime Scales
    • Living Beings Transform Energy and Matter
    • Function Follows Form
    • Positive Feedback Control Systems Have Different Signs for the Adjustment to Perturbations
    • We Are Not Alone: the Microbiota
    • Physiology Is a Quantitative Science
    • Summary
    • Review Questions
  • 1. 2. Physical Foundations of Physiology I: Pressure-Driven Flow
    • Abstract
    • Forces Produce Flows
    • Conservation of Matter or Energy Leads to the Continuity Equation
    • Steady-State Flows Require Linear Gradients
    • Heat, Charge, Solute, and Volume Can Be Stored: Analogues of Capacitance
    • Pressure Drives Fluid Flow
    • Poiseuille’s Law Governs Steady-State Laminar Flow in Narrow Tubes
    • The Law of LaPlace Relates Pressure to Tension in Hollow Organs
    • Summary
    • Review Questions
    • Appendix 1. 2. A1 Derivation of Poiseuille’s Law
    • Appendix 1. 2. A2 Introductory Statistics and Linear Regresssion
  • 1. 3. Physical Foundations of Physiology II: Electrical Force, Potential, Capacitance, and Current
    • Abstract
    • Coulomb’s Law Describes Electrical Forces
    • The Electric Potential Is the Work per Unit Charge
    • The Idea of Potential Is Limited to Conservative Forces
    • The Work Done by a Conservative Force Is Path Independent
    • Potential Difference Depends Only on the Initial and Final States
    • The Electric Field Is the Negative Gradient of the Potential
    • Force and Energy Are Simple Consequences of Potential
    • Gauss’s Law Is a Consequence of Coulomb’s Law
    • The Capacitance of a Parallel Plate Capacitor Depends on Its Area and Plate Separation
    • Biological Membranes Are Electrical Capacitors
    • Electric Charges Move in Response to Electric Forces
    • Movement of Ions in Response to Electrical Forces Makes a Current and a Solute Flux
    • The Relationship Between J and C Defines an Average Velocity
    • Ohm’s Law Relates Current to Potential
    • Kirchhoff’s Current Law and Kirchhoff’s Voltage Law
    • The Time Constant Characterizes the Charging of a Capacitor in a Simple RC Circuit
    • Summary
    • Review Questions
  • Problem Set 1. 1. Physical Foundations: Pressure and Electrical Forces and Flows
  • 1. 4. Chemical Foundations of Physiology I: Chemical Energy and Intermolecular Forces
    • Abstract
    • Atoms Contain Distributed Electrical Charges
    • Electron Orbitals Have Specific, Quantized Energies
    • Human Life Requires Relatively Few of the Chemical Elements
    • Atomic Orbitals Explain the Periodicity of Chemical Reactivities
    • Atoms Bind Together in Definite Proportions to Form Molecules
    • Compounds Have Characteristic Geometries and Surfaces
    • Single CC Bonds Can Freely Rotate
    • Double CC Bonds Prohibit Free Rotation
    • Chemical Bonds Have Bond Energies, Bond Lengths, and Bond Angles
    • Bond Energy Is Expressed as Enthalpy Changes
    • The Multiplicity of CX Bonds Produces Isomerism
    • Unequal Sharing Makes Polar Covalent Bonds
    • Ionic Bonds Result from Atoms with Highly Unequal Electronegativities
    • Water Provides an Example of a Polar Bond
    • Intermolecular Forces Arise from Electrostatic Interactions
    • Hydrogen Bonding Occurs Between Two Electronegative Centers
    • Dipole–Dipole Interactions Are Effective Only Over Short Distances
    • London Dispersion Forces Involve Induced Dipoles
    • Close Approach of Molecules Results in a Repulsive Force That Combines with the van der Waals Forces in the Lennard–Jones Potential
    • Atoms Within Molecules Wiggle and Jiggle, and Bonds Stretch and Bend
    • Summary
    • Review Questions
    • Appendix 1. 4. A1 Dipole Moment
  • 1. 5. Chemical Foundations of Physiology II: Concentration and Kinetics
    • Abstract
    • Avogadro’s Number Counts the Particles in a Mole
    • Concentration Is the Amount Per Unit Volume
    • Scientific Prefixes Indicate Order of Magnitude
    • Dilution of Solutions Is Calculated Using Conservation of Solute
    • Calculation of Fluid Volumes by the Fick Dilution Principle
    • Chemical Reactions Have Forward and Reverse Rate Constants
    • First-Order Rate Equations Show Exponential Decay
    • Rates of Chemical Reactions Depend on the Activation Energy
    • Enzymes Speed Up Reactions by Lowering Ea
    • The Michaelis–Menten Formulation of Enzyme Kinetics
    • Physiology Is All About Surfaces
    • Summary
    • Review Questions
    • Appendix 1. 5. A1 Transition State Theory Explains Reaction Rates in Terms of an Activation Energy
    • Appendix 1. 5. A2 Unidirectional Fluxes Over a Series of Intermediates Depend on All of the Individual Unidirectional Fluxes
    • Appendix 1. 5. A3 Simple Compartmental Analysis
  • 1. 6. Diffusion
    • Abstract
    • Fick’s First Law of Diffusion Was Proposed in Analogy to Fourier’s Law of Heat Transfer
    • Fick’s Second Law of Diffusion Follows from the Continuity Equation and Fick’s First Law
    • Fick’s Second Law Can Be Derived from the One-Dimensional Random Walk
    • The Time for One-Dimensional Diffusion Increases with the Square of Distance
    • Diffusion Coefficients in Cells Are Less than the Free Diffusion Coefficient in Water
    • External Forces Can Move Particles and Alter the Diffusive Flux
    • The Stokes–Einstein Equation Relates the Diffusion Coefficient to Molecular Size
    • Summary
    • Review Questions
    • Appendix 1. 6. A1 Derivation of Einstein’s Frictional Coefficient from Momentum Transfer in Solution
  • 1. 7. Electrochemical Potential and Free Energy
    • Abstract
    • Diffusive and Electrical Forces Can Be Unified in the Electrochemical Potential
    • The Overall Force That Drives Flux Is the Negative Gradient of the Electrochemical Potential
    • The Electrochemical Potential Is the Gibbs Free Energy Per Mole
    • The Sign of ΔG Determines the Direction of a Reaction
    • Processes with ΔG>0 Can Proceed Only by Linking Them with Another Process with ΔG<0
    • The Large Negative Free Energy of ATP Hydrolysis Powers Many Biological Processes
    • Measurement of the Equilibrium Concentrations of ADP, ATP, and Pi Allows Us to Calculate ΔG0
    • Summary
    • Review Questions
  • Problem Set 1. 2. Kinetics and Diffusion
• Unit 2: Membranes, Transport, and Metabolism
  • 2. 1. Cell Structure
    • Abstract
    • For Cells, Form Follows Function
    • Organelles Make Up the Cell Like the Organs Make Up the Body
    • The Cell Membrane Marks the Limits of the Cell
    • The Cytosol Provides a Medium for Dissolution and Transport of Materials
    • The Cytoskeleton Supports the Cell and Forms a Network for Vesicular Transport
    • Microtubules Are the Largest Cytoskeletal Filaments
    • Actin Filaments Arise from Nucleation Sites Usually in the Cell Cortex
    • Intermediate Filaments Are Diverse
    • Cytoskeletal Units Form Free-Floating Structures Based on Tensegrity
    • Myosin Interacts with Actin to Produce Force or Shortening
    • The Nucleus Is the Command Center of the Cell
    • Ribosomes Are the Site of Protein Synthesis
    • The ER Is the Site of Protein and Lipid Synthesis and Processing
    • The Golgi Apparatus Packages Secretory Materials
    • The Mitochondrion Is the Powerhouse of the Cell
    • Lysosomes and Peroxisomes Are Bags of Enzymes
    • Proteasomes Degrade Marked Proteins
    • Cells Attach to Each Other Through a Variety of Junctions
    • Summary
    • Review Questions
    • Appendix 2. 1. A1 Some Methods for Studying Cell Structure and Function
    • Microscopic Resolution Is the Ability to Distinguish Between Two Separated Objects
    • The Electron Microscope Has Advanced Our Understanding of Cell Structure
    • Subcellular Fractionation Allows Studies of Isolated Organelle But Requires Disruption of Cell Function and Structure
    • Differential Centrifugation Produces Enriched Fractions of Subcellular Organelles
    • Density Gradient Centrifugation Enhances Purity of the Fractions
    • Analysis of Centrifugation Separation
    • Centripetal Force in a Spinning Tube Is Provided by the Solvent
    • The Magnitude of the Centripetal Force Can Be Expressed as Relative Centrifugal Force
    • The Velocity of Sedimentation Is Measured in Svedbergs or S Units
    • Density Gradient Centrifugation
    • Other Optical Methods
  • 2. 2. DNA and Protein Synthesis
    • Abstract
    • DNA Makes Up the Genome
    • DNA Consists of Two Intertwined Sequences of Nucleotides
    • RNA Is Closely Related to DNA
    • The Genetic Code Is a System Property
    • Regulation of DNA Transcription Defines the Cell Type
    • The Histone Code Provides Another Level of Regulation of Gene Transcription
    • DNA Methylation Represses Transcription
    • Summary
    • Review Questions
  • 2. 3. Protein Structure
    • Abstract
    • Amino Acids Make Up Proteins
    • Hydrophobic Interactions Can Be Assessed from the Partition Coefficient
    • Peptide Bonds Link Amino Acids Together in Proteins
    • Protein Function Centers on Their Ability to Form Reactive Surfaces
    • There Are Four Levels of Description for Protein Structure
    • Posttranslational Modification Regulates and Refines Protein Structure and Function
    • Protein Activity Is Regulated by the Number of Molecules or by Reversible Activation/Inactivation
    • Summary
    • Review Questions
  • 2. 4. Biological Membranes
    • Abstract
    • Biological Membranes Surround Most Intracellular Organelles
    • Biological Membranes Consist of a Lipid Bilayer Core with Embedded Proteins and Carbohydrate Coats
    • Organic Solvents Can Extract Lipids from Membranes
    • Biological Membranes Contain Mostly Phospholipids
    • Phospholipids Contain Fatty Acyl Chains, Glycerol, Phosphate, and a Hydrophilic Group
    • Plasmanyl Phospholipids and Plasmenyl Phospholipids Use Fatty Alcohols Instead of Fatty Acids
    • Sphingolipids Use Sphingosine as a Backbone and Are Particularly Rich in Brain and Nerve Tissues
    • Other Lipid Components of Membranes Include Cardiolipin, Sphingolipids, and Cholesterol
    • Surface Tension of Water Results from Asymmetric Forces at the Interface
    • Water “Squeezes Out” Amphipathic Molecules
    • Amphipathic Molecules Spread Over a Water Surface, Reduce Surface Tension, and Produce an Apparent Surface Pressure
    • Phospholipids Form Bilayer Membranes Between Two Aqueous Compartments
    • Lipid Bilayers Can Also Form Liposomes
    • Although Lipids Form the Core, Membrane Proteins Carry Out Many of the Functions of Membranes
    • Membrane Proteins Bind to Membranes with Varying Affinity
    • Lipids Maintain Dynamic Motion Within the Bilayer
    • Lipid Rafts Are Special Areas of Lipid and Protein Composition
    • Caveolae and Clathrin-Coated Pits Are Stabilized by Integral Proteins
    • Secreted Proteins Have Special Mechanisms for Getting Inside the Endoplasmic Reticulum
    • Summary
    • Review Questions
  • Problem Set 2. 1. Surface Tension, Membrane Surface Tension, Membrane Structure, Microscopic Resolution, and Cell Fractionation
  • 2. 5. Passive Transport and Facilitated Diffusion
    • Abstract
    • Membranes Possess a Variety of Transport Mechanisms
    • A Microporous Membrane Is One Model of a Passive Transport Mechanism
    • Dissolution in the Lipid Bilayer Is Another Model for Passive Transport
    • Facilitated Diffusion Uses a Membrane-Bound Carrier
    • Facilitated Diffusion Saturates with Increasing Solute Concentrations
    • Facilitated Diffusion Shows Specificity
    • Facilitated Diffusion Shows Competitive Inhibition
    • Passive Transport Occurs Spontaneously Without Input of Energy
    • Ions Can be Passively Transported Across Membranes by Ionophores or by Channels
    • Ionophores Carry Ions Across Membranes or Form Channels
    • Ion Channels
    • Water Moves Passively Through Aquaporins
    • Summary
    • Review Questions
  • 2. 6. Active Transport: Pumps and Exchangers
    • Abstract
    • The Electrochemical Potential Difference Measures the Energetics of Ion Permeation
    • Active Transport Mechanisms Link Metabolic Energy to Transport of Materials
    • Na, K-ATPase Is an Example of Primary Active Transport
    • Na, K-ATPase Forms a Phosphorylated Intermediate
    • The Na, K-ATPase Is Electrogenic
    • There Are Many Different Primary Active Transport Pumps
    • The Na–Ca Exchanger as an Example of Secondary Active Transport
    • Secondary Active Transport Mechanisms Are Symports or Antiports
    • Summary
    • Review Questions
    • Appendix 2. 6. A1 Derivation of the Ussing Flux Ratio Equation
    • Appendix 2. 6. A2 Nomenclature of Transport Proteins
    • Carrier Classifications
    • Solute Carriers
    • ATP-Driven Ion Pumps
    • ABC Transporters
    • Aquaporins
  • 2. 7. Osmosis and Osmotic Pressure
    • Abstract
    • Osmosis Is the Flow of Water Driven by Solute Concentration Differences
    • The van’t Hoff Equation Relates Osmotic Pressure to Concentration
    • Thermodynamic Derivation of van’t Hoff’s Law
    • Osmotic Pressure Is a Property of Solutions Related to Other Colligative Properties
    • The Osmotic Coefficient φ Corrects for the Assumption of Dilute Solution and for Nonideal Behavior
    • The Rational Osmotic Coefficient Corrects for the Assumption of Ideality
    • Equivalence of Osmotic and Hydrostatic Pressures
    • The Reflection Coefficient Corrects van’t Hoff’s Equation for Permeable Solutes
    • Lp for a Microporous Membrane Depends on the Microscopic Characteristics of the Membrane
    • Case 1: The Solute Is Very Small Compared to the Pore
    • Case 2: The Solute Is Larger than the Pore: The Mechanism of Osmosis for Microporous Membranes
    • Case 3: The Reflection Coefficient Results from Partially Restricted Entry of Solutes into the Pores
    • Solutions May Be Hypertonic or Hypotonic
    • Osmosis, Osmotic Pressure, and Tonicity Are Related But Distinct Concepts
    • Cells Behave Like Osmometers
    • Cells Actively Regulate Their Volume Through RVDs and RVIs
    • Summary
    • Review Questions
    • Appendix 2. 7. A1 Mechanism of Osmosis: Filtration Versus Diffusion Down a Concentration Gradient
  • Problem Set 2. 2. Membrane Transport
  • 2. 8. Cell Signaling
    • Abstract
    • Signaling Transduces One Event into Another
    • Cell-to-Cell Communication Can Also Use Direct Mechanical, Electrical, or Chemical Signals
    • Signals Elicit a Variety of Classes of Cellular Responses
    • Electrical Signals and Neurotransmitters Are Fastest; Endocrine Signals Are Slowest
    • Voltage-Gated Ion Channels Convey Electrical Signals
    • Voltage-Gated Ca2+ Channels Transduce an Electrical Signal to an Intracellular Ca2+ Signal
    • Ligand-Gated Ion Channels Open Upon Binding with Chemical Signals
    • Heterotrimeric G-Protein-Coupled Receptors (GPCRs) Are Versatile
    • There Are Four Classes of G-Proteins: Gαs, Gαi/Gαo, Gαq, and Gα12/Gα13
    • The Response of a Cell to a Chemical Signal Depends on the Receptor and Its Effectors
    • Chemical Signals Can Bind to and Directly Activate Membrane-Bound Enzymes
    • Many Signals Alter Gene Expression
    • Nuclear Receptors Alter Gene Transcription
    • Nuclear Receptors Recruit Histone Acetylase to Unwrap the DNA from the Histones
    • Nuclear Receptors Recruit Transcription Factors
    • Other Signaling Pathways Also Regulate Gene Expression
    • Summary of Signaling Mechanisms
    • Summary
    • Review Questions
  • 2. 9. ATP Production I: Glycolysis
    • Abstract
    • Take a Global View of Metabolism
    • Energy Production Occurs in Three Stages: Breakdown into Units, Formation of Acetyl CoA, and Complete Oxidation of Acetyl CoA
    • ATP Is the Energy Currency of the Cell
    • Fuel Reserves Are Stored in the Body Primarily in Fat Depots and Glycogen
    • Glucose Is a Readily Available Source of Energy
    • Glucose Release by the Liver Is Controlled by Hormones Through a Second Messenger System
    • The Liver Exports Glucose into the Blood Because It Can Dephosphorylate Glucose-6-P
    • A Specific Glucose Carrier Takes Glucose up into Cells
    • Glycolysis Is a Series of Biochemical Transformations Leading from Glucose to Pyruvate
    • Glycolysis Generates ATP Quickly in the Absence of Oxygen
    • Glycolysis Requires NAD+
    • Gluconeogenesis Requires Reversal of Glycolysis
    • Summary
    • Review Questions
  • 2. 10. ATP Production II: The TCA Cycle and Oxidative Phosphorylation
    • Abstract
    • Oxidation of Pyruvate Occurs in the Mitochondria via the TCA Cycle
    • Pyruvate Enters the Mitochondria and Is Converted to Acetyl CoA
    • Pyruvate Dehydrogenase Releases CO2 and Makes NADH
    • The Affinity of a Chemical for Electrons Is Measured by Its Standard Reduction Potential
    • The Reduction Potential Depends on the Concentration of Oxidized and Reduced Forms, and the Temperature
    • The TCA Cycle Is a Catalytic Cycle
    • The ETC Links Chemical Energy to H+ Pumping Out of the Mitochondria
    • Oxygen Accepts Electrons at the End of the ETC
    • Proton Pumping and Electron Transport Are Tightly Coupled
    • The ATP Synthase Couples Inward H+ Flux to ATP Synthesis
    • The Proton Electrochemical Gradient Provides the Energy for ATP Synthesis
    • NADH Forms About 2. 5 ATP Molecules; FADH2 Forms About 1. 5 ATP Molecules
    • ATP Can Be Produced From Cytosolic NADH
    • Most of the ATP Produced During Complete Glucose Oxidation Comes from Oxidative Phosphorylation
    • Mitochondria Have Specific Transport Mechanisms
    • Summary
    • Review Questions
  • 2. 11. ATP Production III: Fatty Acid Oxidation and Amino Acid Oxidation
    • Abstract
    • Fats and Proteins Contribute 50% of the Energy Content of Many Diets
    • Depot Fat Is Stored as Triglycerides and Broken Down to Glycerol and Fatty Acids for Energy
    • Glycerol Is Converted to an Intermediate of Glycolysis
    • Fatty Acids Are Metabolized in the Mitochondria and Peroxisomes
    • Beta Oxidation Cleaves Two Carbon Pieces off Fatty Acids
    • The Liver Packages Substrates for Energy Production by Other Tissues
    • Amino Acids Can Be Used to Generate ATP
    • Amino Acids Are Deaminated to Enable Oxidation
    • Urea Is Produced During Deamination and Is Eliminated as a Waste Product
    • Summary
    • Review Questions
• Unit 3: Physiology of Excitable Cells
  • 3. 1. The Origin of the Resting Membrane Potential
    • Abstract
    • Introduction
    • The Equilibrium Potential Arises from the Balance Between Electrical Force and Diffusion
    • The Equilibrium Potential for K+ Is Negative
    • Integration of the Nernst–Planck Electrodiffusion Equation Gives the Goldman–Hodgkin–Katz Equation
    • Slope Conductance and Chord Conductance Relate Ion Flows to the Net Driving Force
    • The Chord Conductance Equation Relates Membrane Potential to All Ion Flows
    • The Current Convention Is that an Outward Current Is Positive
    • Summary
    • Review Questions
    • Appendix 3. 1. A1 Derivation of the GHK Equation
  • 3. 2. The Action Potential
    • Abstract
    • Cells Use Action Potentials as Fast Signals
    • The Motor Neuron Has Dendrites, a Cell Body, and an Axon
    • Passing a Current Across the Membrane Changes the Membrane Potential
    • An Outward Current Hyperpolarizes the Membrane Potential
    • The Result of Depolarizing Stimulus of Adequate Size Is a New Phenomenon—the Action Potential
    • The Action Potential Is All or None
    • The Latency Decreases with Increasing Stimulus Strength
    • Threshold Is the Membrane Potential at Which an Action Potential Is Elicited 50% of the Time
    • The Nerve Cannot Produce a Second Excitation During the Absolute Refractory Period
    • The Action Potential Reverses to Positive Values, Called the Overshoot
    • The Strength–Duration Relationship is Hyperbolic
    • Voltage-Dependent Changes in Ion Conductance Cause the Action Potential
    • The Action Potential Is Accompanied by Na+ Influx
    • The Chord Conductance Equation Predicts that Changes in Conductance Will Change the Membrane Potential
    • gNa Increases Transiently During the Action Potential; gK Increases Later and Stays Elevated Longer
    • Conductance and Equilibrium Potentials for Na+ and K+ Account for All of the Features of the Action Potential
    • gNa Is a Function of a Na+-Selective Channel
    • The Inactivation Gates Must Be Reset Before Another Action Potential Can Be Fired
    • Conductance Depends on the Number and State of the Channels
    • Patch Clamp Experiments Measure Unitary Conductances
    • The Current–Voltage Relationship for the Whole Cell Determines the Threshold for Excitation
    • Threshold Depolarization Requires a Threshold Charge Movement, Which Explains the Strength–Duration Relationship
    • The Amount of Charge Necessary to Reach Threshold Explains the Strength–Duration Relationship
    • Summary
    • Review Questions
    • Appendix 3. 2. A1 The Hodgkin–Huxley Model of the Action Potential
    • The HH Model Divides the Total Current into Separate Na+, K+, and Leak Currents
    • The HH Model of the K+ Conductance Incorporates Four Independent “Particles”
    • The HH Model of Na+ Conductances Uses Activating and Inactivating Particles
    • Calculation of gNa(t) and gK(t) for a Voltage Clamp Experiment
    • Results of the Calculations
  • 3. 3. Propagation of the Action Potential
    • Abstract
    • The Action Potential Moves Along the Axon
    • The Velocity of Nerve Conduction Varies Directly with the Axon Diameter
    • The Action Potential Is Propagated by Current Moving Axially Down the Axon
    • The Time Course and Distance of Electrotonic Spread Depend on the Cable Properties of the Nerve
    • Capacitance Depends on the Area, Thickness, and Dielectric Constant
    • Charge Buildup or Depletion from a Capacitor Constitutes a Capacitative Current
    • The Transmembrane Resistance Depends on the Area of the Membrane
    • The Axoplasmic Resistance Depends on the Distance, Area, and Specific Resistance
    • The Extracellular Resistance Also Depends on the Distance, Area, and Specific Resistance
    • Cable Properties Define a Space Constant and a Time Constant
    • The Cable Properties Explain the Velocity of Action Potential Conduction
    • Saltatory Conduction Refers to the “Jumping” of the Current from Node to Node
    • The Action Potential Is Spread out Over More than One Node
    • Summary
    • Review Questions
    • Appendix 3. 3. A1 Capacitance of a Coaxial Capacitor
    • The Capacitance of a Coaxial Cable
  • Problem Set 3. 1. Membrane Potential, Action Potential, and Nerve Conduction
  • 3. 4. Skeletal Muscle Mechanics
    • Abstract
    • Muscles Either Shorten or Produce Force
    • Muscles Perform Diverse Functions
    • Muscles Are Classified According to Fine Structure, Neural Control, and Anatomical Arrangement
    • Isometric Force Is Measured While Keeping Muscle Length Constant
    • Muscle Force Depends on the Number of Motor Units That Are Activated
    • The Size Principle States That Motor Units Are Recruited in the Order of Their Size
    • Muscle Force Can Be Graded by the Frequency of Motor Neuron Firing
    • Muscle Force Depends on the Length of the Muscle
    • Recruitment Provides the Greatest Gradation of Muscle Force
    • Muscle Fibers Differ in Contractile, Metabolic and Proteomic Characteristics
    • Motor Units Contain a Single Type of Muscle Fiber
    • The Innervation Ratio of Motor Units Produces a Proportional Control of Muscle Force
    • Muscle Force Varies Inversely with Muscle Velocity
    • Muscle Power Varies with the Load and Muscle Type
    • Eccentric Contractions Lengthen the Muscle and Produce More Force
    • Concentric, Isometric, and Eccentric Contractions Serve Different Functions
    • Muscle Architecture Influences Force and Velocity of the Whole Muscle
    • Muscles Decrease Force Upon Repeated Stimulation; This Is Fatigue
    • Summary
    • Review Questions
  • 3. 5. Contractile Mechanisms in Skeletal Muscle
    • Abstract
    • Introduction
    • Muscle Fibers Have a Highly Organized Structure
    • The Sliding Filament Hypothesis Explains the Length–Tension Curve
    • Force Is Produced by an Interaction Between Thick Filament Proteins and Thin Filament Proteins
    • The Thin Filament Consists Primarily of Actin
    • α-Actinin at the Z-disk Joins Actin Filaments of Adjacent Sarcomeres
    • Myomesin Joins Thick Filaments at the M-Line or M-Band
    • Overall Structure of the Sarcomere Is Complicated
    • Cross-Bridges from the Thick Filament Split ATP and Generate Force
    • Myosin Heads Are Independent But May Cooperate Through Strain on the Cross-Bridge
    • Cross-Bridge Cycling Rate Explains the Fiber-Type Dependence of the Force–Velocity Curve
    • Force Is Transmitted Outside the Cell Through the Cytoskeleton and Special Transmembrane Proteins
    • Summary
    • Review Questions
  • 3. 6. The Neuromuscular Junction and Excitation–Contraction Coupling
    • Abstract
    • Motor Neurons Are the Sole Physiological Activators of Skeletal Muscles
    • The Motor Neuron Receives Thousands of Inputs from Other Cells
    • Postsynaptic Potentials Can Be Excitatory or Inhibitory
    • Postsynaptic Potentials Are Graded, Spread Electrotonically, and Decay with Time
    • Action Potentials Originate at the Initial Segment or Axon Hillock
    • Motor Neurons Integrate Multiple Synaptic Inputs to Initiate Action Potentials
    • The Action Potential Travels Down the Axon Toward the Neuromuscular Junction
    • The Neuromuscular Junction Consists of Multiple Enlargements Connected by Axon Segments
    • Neurotransmission at the Neuromuscular Junction Is Unidirectional
    • Motor Neurons Release Acetylcholine to Excite Muscles
    • Ca2+ Efflux Mechanisms in the Presynaptic Cell Shut Off the Ca2+ Signal
    • Acetylcholine Is Degraded and Then Recycled
    • The Action Potential on the Muscle Membrane Propagates Both Ways on the Muscle
    • The Muscle Fiber Converts the Action Potential into an Intracellular Ca2+ Signal
    • The Ca2+ during E–C Coupling Originates from the Sarcoplasmic Reticulum
    • Ca2+ Release from the SR and Reuptake by the SR Requires Several Proteins
    • Reuptake of Ca2+ by the SR Ends Contraction and Initiates Relaxation
    • Cross-Bridge Cycling Is Controlled by Myoplasmic [Ca2+]
    • Sequential SR Release and Summation of Myoplasmic [Ca2+] Explains Summation and Tetany
    • The Elastic Properties of the Muscle Are Responsible for the Waveform of the Twitch
    • Repetitive Stimulation Causes Repetitive Ca2+ Release from the SR and Wave Summation
    • Summary
    • Review Questions
    • Appendix 3. 6. A1 Molecular Machinery of the Neuromuscular Junction
    • Appendix 3. 6. A2 Molecular Machinery of the Calcium Release Unit
  • 3. 7. Muscle Energetics, Fatigue, and Training
    • Abstract
    • Muscular Activity Relies on the Free Energy of ATP Hydrolysis
    • Muscular Activity Consumes ATP at High Rates
    • The Aggregate Rate and Amount of ATP Consumption Varies with the Intensity and Duration of Exercise
    • In Repetitive Exercise, Intensity Increases Frequency and Reduces Rest Time
    • Metabolic Pathways Regenerate ATP on Different Timescales and with Different Capacities
    • The Metabolic Pathways Used by Muscle Varies with Intensity and Duration of Exercise
    • At High Intensity of Exercise, Glucose and Glycogen Are the Preferred Fuel for Muscle
    • Lactic Acid Produced by Anaerobic Metabolism Allows High Glycolytic Flux
    • Muscle Fibers Differ in Their Metabolic Properties
    • Blood Lactate Levels Rise Progressively with Increases in Exercise Intensity
    • Mitochondria Import Lactic Acid, Then Metabolize it; This Forms a Carrier System for NADH Oxidation
    • Lactate Shuttles to the Mitochondria, Oxidative Fibers, or Liver
    • The “Anaerobic Threshold” Results from a Mismatch of Lactic Acid Production and Oxidation
    • Exercise Increases Glucose Transporters in the Muscle Sarcolemma
    • Fatigue Is a Transient Loss of Work Capacity Resulting from Preceding Work
    • Initial Training Gains Are Neural
    • Muscle Strength Depends on Muscle Size
    • Endurance Training Uses Repetitive Movements to Tune Muscle Metabolism
    • Endocrine and Autocrine Signals Regulate Muscle Size (=Strength)
    • Human Ability to Switch Muscle Fiber Types Is Limited
    • Summary
    • Review Questions
  • Problem Set 3. 2. Neuromuscular Transmission, Muscle Force, and Energetics
  • 3. 8. Smooth Muscle
    • Abstract
    • Smooth Muscles Show No Cross-Striations
    • Smooth Muscle Develops Tension More Slowly But Can Maintain Tension for a Long Time
    • Smooth Muscle Can Contract Tonically or Phasically
    • Smooth Muscles Exhibit a Variety of Electrical Activities that May or May Not Be Coupled to Force Development
    • Contractile Filaments in Smooth Muscle Cells Form a Lattice That Attaches to the Cell Membrane
    • Adjacent Smooth Muscle Cells Are Mechanically Coupled and May Be Electrically Coupled
    • Smooth Muscle Is Controlled by Intrinsic Activity, Nerves, and Hormones
    • Nerves Release Neurotransmitters Diffusely onto Smooth Muscle
    • Contraction in Smooth Muscle Cells Is Initiated by Increasing Intracellular [Ca2+]
    • Smooth Muscle Cytosolic [Ca2+] Is Heterogeneous and Controlled by Multiple Mechanisms
    • Smooth Muscle [Ca2+] Can Be Regulated by Chemical Signals
    • Force in Smooth Muscle Arises from Ca2+ Activation of Actin–Myosin Interaction
    • Myosin Light Chain Phosphorylation Regulates Smooth Muscle Force
    • Myosin Light Chain Phosphatase Dephosphorylates the RLC
    • Ca2+ Sensitization Produces Force at Lower [Ca2+] Levels
    • Nitric Oxide Induces Smooth Muscle Relaxation by Stimulating Guanylate Cyclase
    • Adrenergic Stimulation Relaxes Smooth Muscles by Reducing Cytosolic [Ca2+]
    • Synopsis of Mechanisms Promoting Contraction or Relaxation of Smooth Muscle
    • Summary
    • Review Questions
• Unit 4: The Nervous System
  • 4. 1. Organization of the Nervous System
    • Abstract
    • The Neuroendocrine System Controls Physiological Systems
    • A Central Tenet of Physiological Psychology Is That Neural Processes Completely Explain All Behavior
    • The New Mind–Body Problem Is How Consciousness Arises from a Material Brain
    • External Behavioral Responses Require Sensors, Internal Processes, and Motor Response
    • The Nervous System Is Divided into the Central and Peripheral Nervous System
    • The Brain Has Readily Identifiable Surface Features
    • CSF Fills the Ventricles and Cushions the Brain
    • The Blood-Brain Barrier Protects the Brain
    • Cross Sections of the Brain and Staining Reveal Internal Structures
    • Gray Matter Is Organized into Layers
    • Overall Function of the Nervous System Derives from its Component Cells
    • Overview of the Functions of Some Major Areas of the CNS
    • Summary
    • Review Questions
  • 4. 2. Cells, Synapses, and Neurotransmitters
    • Abstract
    • Nervous System Behavior Derives from Cell Behavior
    • Nervous Tissue Is Composed of Neurons and Supporting Cells
    • Glial Cells Protect and Serve
    • Neurons Differ in Shapes and Size
    • Input Information Typically Converges on the Cell and Output Information Diverges
    • Chemical Synapses Are Overwhelmingly More Common
    • Ca2+ Signals Initiate Chemical Neurotransmission
    • Vesicle Fusion Uses the Same Molecular Machinery That Regulates Other Vesicle Traffic
    • Ca2+ Efflux Mechanisms in the Pre-Synaptic Cell Shut Off the Ca2+ Signal
    • Removal or Destruction of the Neurotransmitter Shuts Off the Neurotransmitter Signal
    • The Pre-Synaptic Terminal Recycles Neurotransmitter Vesicles
    • Ionotropic Receptors Are Ligand-Gated Channels; Metabotropic Receptors Are GPCR
    • Acetylcholine Binds to Nicotinic Receptors or Muscarinic Receptors
    • Catecholamines: Dopamine, Norepinephrine, and Epinephrine Derive from Tyrosine
    • Dopamine Couples to Gs and Gi-Coupled Receptors through D1 and D2 Receptors
    • Adrenergic Receptors Are Classified According to Their Pharmacology
    • Glutamate and Aspartate Are Excitatory Neurotransmitters
    • GABA Inhibits Neurons
    • Serotonin Exerts Multiple Effects in the PNS and CNS
    • Neuropeptides Are Synthesized in the Soma and Transported via Axonal Transport
    • Summary
    • Review Questions
  • 4. 3. Cutaneous Sensory Systems
    • Abstract
    • Sensors Provide a Window onto Our World
    • Exteroreceptors Include the Five Classical Senses and the Cutaneous Senses
    • Interoreceptors Report on the Chemical and Physical State of the Interior of the Body
    • Sensory Systems Consist of the Sense Organ, the Sensory Receptors, and the Pathways to the CNS
    • Perception Refers to Our Awareness of a Stimulus
    • Long and Short Receptors Differ in Their Production of Action Potentials
    • Anatomical Connection Determines the Quality of a Sensory Stimulus
    • The Intensity of Sensory Stimuli Is Encoded by the Frequency of Sensory Receptor Firing and the Population of Active Receptors
    • Frequency Coding is the Basis of the Weber–Fechner Law of Psychology
    • Adaptation to a Stimulus Allows Sensory Neurons to Signal Position, Velocity, and Acceleration
    • Receptive Fields Refer to the Physical Areas at Which a Stimulus Will Excite a Receptor
    • Cutaneous Receptors Include Mechanoreceptors, Thermoreceptors, and Nociceptors
    • Somatosensory Information Is Transmitted to the Brain through the Dorsal Column Pathway
    • The Cutaneous Senses Map onto the Sensory Cortex
    • Pain and Temperature Information Travel in the Anterolateral Tract
    • Disorders of Sensation Can Pinpoint Damage
    • Pain Sensation Can Be Reduced by Somatosensory Input
    • The Receptive Field of Somatosensory Cortical Neurons is Often On-Center, Off-Surround
    • Summary
    • Review Questions
  • 4. 4. Spinal Reflexes
    • Abstract
    • A Reflex is a Stereotyped Muscular Response to a Specific Sensory Stimulus
    • The Withdrawal Reflex Protects Us from Painful Stimuli
    • The Crossed-Extensor Reflex Usually Occurs in Association with the Withdrawal Reflex
    • The Myotatic Reflex Involves a Muscle Length Sensor, the Muscle Spindle
    • The Muscle Spindle Is a Specialized Muscle Fiber
    • The Myotatic Reflex Is a MonoSynaptic Reflex Between Ia Afferents and the α Motor Neuron
    • The Gamma Motor System Maintains Tension on the Intrafusal Fibers During Muscle Contraction
    • The Inverse Myotatic Reflex Involves Sensors of Muscle Force in the Tendon
    • The Spinal Cord Possesses Other Reflexes and Includes Locomotor Pattern Generators
    • The Spinal Cord Contains Descending Tracts That Control Lower Motor Neurons
    • All of the Inputs to the Lower Motor Neurons Form Integrated Responses
    • Summary
    • Review Questions
  • 4. 5. Balance and Control of Movement
    • Abstract
    • The Nervous System Uses a Population Code and Frequency Code to Control Contractile Force
    • Control of Movement Entails Control of α Motoneuron Activity
    • The Circuitry of the Spinal Cord Provides the First Layer in a Hierarchy of Muscle Control
    • The Motor Nerves Are Organized by Myotomes
    • Spinal Reflexes Form the Basis of Motor Control
    • Purposeful Movements Originate in the Cerebral Cortex
    • The Primary Motor Cortex Has a Somatotopic Organization
    • Motor Activity Originates from Sensory Areas Together with Premotor Areas
    • Motor Control Is Hierarchical and Serial
    • The Basal Ganglia and Cerebellum Play Important Roles in Movement
    • The Substantia Nigra Sets the Balance Between the Direct and Indirect Pathways
    • The Cerebellum Maintains Movement Accuracy
    • The Sense of Balance Originates in Hair Cells in the Vestibular Apparatus
    • Rotation of the Head Gives Opposite Signals from the Two Vestibular Apparatuses
    • The Utricles and Saccules Contain Hair Cells That Respond to Static Forces of Gravity
    • The Afferent Sensory Neurons from the Vestibular Apparatus Project to the Vestibular Nuclei in the Medulla
    • Summary
    • Review Questions
  • Problem Set 4. 1. Nerve Conduction
    • Abstract
  • 4. 6. The Chemical Senses
    • Abstract
    • The Chemical Senses Include Taste and Smell
    • Taste and Olfactory Receptors Turn Over Regularly
    • The Olfactory Epithelium Resides in the Roof of the Nasal Cavities
    • Olfactory Receptor Cells Send Axons Through the Cribriform Plate
    • Humans Recognize a Wide Variety of Odors But Are Often Untrained in Their Identification
    • The Response to Specific Odorants Is Mediated by Specific Odorant Binding Proteins
    • The Olfactory Receptor Cells Send Axons to Second-Order Neurons in the Olfactory Bulb
    • Each Glomerulus Corresponds to One Receptor That Responds to Its Molecular Receptive Range
    • Olfaction Requires Pattern Recognition Over About 350 Input Channels
    • Olfactory Output Connects Directly to the Cortex in the Temporal Lobe
    • A Second Olfactory Output Is Through the Thalamus to the Orbitofrontal Cortex
    • The Detection Limits for Odors Can Be Low
    • Adaptation to Odors Involves the Central Nervous System
    • Some “Smells” Stimulate the Trigeminal Nerve and Not the Olfactory Nerve
    • Humans Distinguish Among Five Primary Types of Taste Sensations
    • The Taste Buds Are Groups of Taste Receptors Arranged on Taste Papillae
    • TRCs Respond to Single Modalities
    • Salty Taste Has Two Mechanisms Distinguished by Their Amiloride Sensitivity
    • Sour Taste Depends on TRC Cytosolic pH
    • Sweet, Bitter, and Umami Taste Are Transduced by Three Sets of G-Protein-Coupled Receptors
    • The “Hot” Taste of Jalapeno Peppers Is Sensed Through Pain Receptors
    • Taste Receptors Project to the Cortex Through the Solitary Nucleus and the Thalamus
    • Flavor Is in the Brain
    • Summary
    • Review Questions
  • 4. 7. Hearing
    • Abstract
    • The Human Auditory System Discriminates Among Tone, Timbre, and Intensity
    • The Auditory System Can Locate Sources of Noise Using Time Delays and Intensity Differences
    • The Ear Consists of Three Parts: the Outer Ear, Middle Ear, and Inner Ear: Each Has a Definite Function
    • Hair Cells of the Cochlea Respond to Deformation of Stereocilia Touching the Tectorial Membrane
    • Outer Hair Cells Move in Response to Efferent Stimulation and Thereby Tune the Inner Hair Cells
    • The Cochlea Produces a Tonotopic Mapping of Sound Frequency
    • Auditory Information Passes Through the Brain Stem to the Auditory Cortex
    • Language is Processed in Areas Near the Primary Auditory Cortex in the Left Hemisphere, but Music Is Processed in the Right Hemisphere
    • Perception of Pitch Is Accomplished by a Combination of Tuning and Phase Locking
    • The Cochlear Microphonic Shows that the Inner Hair Cells Have an AC Response That Can Keep up with Moderate Frequency Vibrations
    • Summary
    • Review Questions
    • Appendix 4. 7. A1 The Physics of Sound
  • 4. 8. Vision
    • Abstract
    • Overview of the Visual System
    • The Structure of the Eye Enables Focusing of Light on the Retina
    • The Vitreous Body Maintains Eye Shape
    • The Eye Focuses Light on the Retina by Refraction
    • The Lens Changes Shape to Focus Near Objects
    • Near-Sightedness and Far-Sightedness Are Problems in Focusing the Image on the Retina
    • Photoreceptor Cells in the Retina Transduce Light Signals
    • The Retina Consists of Several Layers and Begins Processing of Visual Signals
    • Bipolar Cells Are Off-Center or On-Center
    • The Output of Bipolar Cells Converge Onto On-Center and Off-Center Ganglion Cells
    • Signals from the Two Eyes Cross Over During the Central Visual Pathways
    • Some Ganglion Cells Project to Other Areas of the Brain
    • Additional Processing of Visual Images Occurs in the Visual Cortex
    • The Visual Cortex Sends Output to the Temporal and Parietal Lobes
    • We Still Do Not Know How We Perceive Visual Images
    • Summary
    • Review Questions
    • Appendix 4. 8. A1 Refraction of Light and the Thin Lens Formula
  • 4. 2 Problem Set. Sensory Transduction
  • 4. 9. Autonomic Nervous System
    • Abstract
    • The Autonomic Nervous System Serves a Homeostatic Function and an Adaptive Function
    • Autonomic Reflexes Are Fast
    • The Emotional State Greatly Affects Autonomic Efferent Function
    • Autonomic Efferent Nerves Have Two Neurons
    • The Sympathetic Nervous System Originates in the Thoracolumbar Spinal Cord
    • The Parasympathetic Nervous System Originates in Cranial and Sacral Nerves
    • Autonomic Reflexes Link Sensory Input to Motor Efferents
    • The Major Autonomic Neurotransmitters Are Acetylcholine and Norepinephrine
    • Parasympathetic Release of Acetylcholine Works on MuscarinicReceptors
    • Norepinephrine Released by Postganglionic Sympathetic Neurons Acts Through α- and β-Receptors
    • Autonomic Nerve Terminals Also Release Other Neurotransmitters
    • Effects of Autonomic Stimulation Depend on the Receptor on the Target Cell
    • The Pupillary Light Reflex Regulates Light Intensity Falling on the Retina: A Parasympathetic Reflex
    • Micturition Involves Autonomic Reflexes and Volitional Nervous Activity
    • Summary
    • Review Questions
• Unit 5: The Cardiovascular System
  • 5. 1. Overview of the Cardiovascular System and the Blood
    • Abstract
    • The Circulatory System Is a Transport System
    • The Circulatory System Consists of the Heart, Blood Vessels, and Blood
    • The Circulatory System Carries Nutrients, Wastes, Chemical Signals, and Heat
    • The Circulation Is Necessary Because Diffusion from and to the Environment Is Too Slow
    • The Circulatory System Consists of the Pulmonary Circulation and Systemic Circulation
    • Most Circulatory Beds Are Arranged in Parallel
    • Pressure Drives Blood Flow Through the Vascular System
    • Vessels Are Characterized by a Compliance
    • Blood Consists of Cells Suspended in Plasma
    • Hemostasis Defends the Integrity of the Vascular Volume
    • Blood Coagulation Sits on a Knife Edge of Activation and Inhibition
    • Summary
    • Review Questions
  • 5. 2. Plasma and Red Blood Cells
    • Abstract
    • Plasma Consists Mainly of Water, Electrolytes, and Proteins
    • Plasma Proteins and Ions Buffer Changes in Plasma pH
    • The Oncotic Pressure of Plasma Proteins Retains Circulatory Volume
    • The Erythrocyte Is the Most Abundant Cell in the Blood
    • Erythrocytes Contain a Lot of Hemoglobin
    • Hemoglobin Consists of Four Polypeptide Chains, Each with a Heme Group
    • Erythropoietin Controls Formation of Erythrocytes from Pluripotent Stem Cells in Bone Marrow
    • Phagocytes in the Reticuloendothelial System Destroy Worn Erythrocytes
    • Iron Recycles into New Heme
    • Human Blood Can Be Classified into a Small Number of Blood Types
    • Summary
    • Review Questions
  • 5. 3. White Blood Cells and Inflammation
    • Abstract
    • The White Blood Cells Include Neutrophils, Eosinophils, Basophils, Monocytes, Lymphocytes, and Platelets
    • White Blood Cells Originate from Pluripotent Stem Cells
    • Neutrophils Are Phagocytes
    • Monocytes Leave the Circulatory System to Become Tissue Macrophages
    • Basophils Resemble Mast Cells
    • Eosinophils Are Involved in Defense of Parasitic Infections and Allergies
    • Lymphocytes Form a Specific Defense System
    • Tissue Macrophages, Monocytes, and Specialized Endothelial Cells Form the Reticuloendothelial System
    • Inflammation Is the Net Response of the Body to Tissue Injury
    • Inflammation Begins with the Release of Signaling Molecules from the Damaged Tissue
    • The Innate Immune Response Requires No Prior Exposure–Specificity of the Response Is Inherited in the Genome
    • Neutrophils and Monocytes Leave the Circulatory System by Diapedesis in Response to Chemotaxic Compounds
    • The Complement System Destroys Microbes that Have Attached Antibodies
    • Summary
    • Review Questions
  • 5. 4. The Heart as a Pump
    • Abstract
    • The Heart Is Located in the Center of the Thoracic Cavity
    • The Heart Is a Muscle
    • Contraction of Cardiac Muscle Produces a Pressure within the Chamber
    • Blood is Pumped through Four Chambers
    • The Four Valves Are Nearly CoPlanar
    • Closure of the Valves Produces the Heart Sounds
    • Additional Turbulence Causes Heart Murmurs
    • Summary of the Contractile Events in the Cardiac Cycle
    • An Automatic Electrical System Controls the Contraction of the Heart
    • Summary
    • Review Questions
  • Problem Set 5. 1. Blood
  • 5. 5. The Cardiac Action Potential
    • Abstract
    • Different Cardiac Cells Differ in Their Resting Membrane Potential and Action Potential
    • SA Nodal Cells Spontaneously Generate Action Potentials Whereas Contractile Cells Have Stable Resting Membrane Potentials
    • Autonomic Nerves Alter the Heart Rate by Affecting the Pacemaker Potential
    • The Ionic Basis of the Ventricular Cardiomyocyte Action Potential
    • Epinephrine Enhances the L-Type Ca2+ Channels, Which Elevates the Action Potential Plateau
    • The Action Potential Is Conducted to Neighboring Cells through Gap Junctions in the Intercalated Disks
    • Summary
    • Review Questions
  • 5. 6. The Electrocardiogram
    • Abstract
    • The ECG is the Projection of Cardiac Electrical Activity onto the Body Surface
    • The Heart Muscle Fibers Act as Electric Dipoles
    • Einthoven Idealized the Thorax as a Triangle
    • The Heart’s Electric Dipole Moment Varies with Time—and so Does its Recording on Leads I, II, and III
    • The Values of Leads I and III Can Be Used to Calculate the Electric Dipole Moment of the Heart
    • Atrial Depolarization Causes the P wave
    • Sequential Depolarization of the Ventricles Produces the QRS Complex
    • The Subepicardium Repolarizes before the Subendocardium, Causing an Upright T wave
    • The Cardiac Dipole Traces a Closed Curve during Each Heart Beat
    • The Largest Depolarization Defines the Mean Electrical Axis
    • Unipolar Leads Record the Difference between an Electrode and a Zero Electrode
    • Augmented Unipolar Limb Leads Use Combination of Only Two Electrodes for the Indifferent Electrode
    • The Einthoven Triangle is Only Approximately Valid
    • The Cardiac Cycle, Revisited
    • Summary
    • Review Questions
  • 5. 7. The Cellular Basis of Cardiac Contractility
    • Abstract
    • Cardiac Muscle Shares Many Structural Features with Skeletal Muscle
    • Intercalated Disks Electrically Couple Cardiomyocytes
    • The Strength of Cardiac Muscle Contraction Is not Regulated by Recruitment or by Summation
    • Cardiac Myofibrils Have Thick and Thin Filaments and Form the Cross-Striations
    • Actin-Activated Myosin ATPase Activity Produces Force and Shortening
    • Cytoplasmic [Ca2+] Controls Actomyosin Cross-Bridge Cycling
    • Calcium-Induced Calcium Release Couples Excitation to Contraction in Cardiac Muscle
    • Reuptake of Ca2+ by the SR and SL Extrusion of Ca2+ Cause Relaxation
    • Mitochondria Can Take Up Ca2+
    • Calsequestrin Augments SR Ca2+ Uptake and Release
    • What Regulates Cardiac Contractility?
    • The Force Generally Increases with the Frequency of the Heart Beat: The Force–Frequency Relation
    • Sympathetic Stimulation Increases Force by Increasing the Ca2+ Transient
    • Parasympathetic Stimulation Opposes Sympathetic Effects (see Figure 5. 7. 7)
    • Cardiac Glycosides Increase Cardiac Contractility by Increasing the Ca2+ Transient
    • Cardiac Contractile Force Is Powerfully Modulated by Stretch
    • Summary
    • Review Questions
  • 5. 8. The Cardiac Function Curve
    • Abstract
    • Cardiac Output Is the Flow Produced by the Heart
    • Stroke Volume Is Determined by Preload, Afterload, and Contractility
    • The Integral of the Pressure–Volume Loop Is the PV Work
    • Total Work of the Heart Includes Pressure, Kinetic, and Gravitational Terms
    • Stretch of the Heart Determines the Stroke Volume: The Frank–Starling Law of the Heart
    • The Ventricular Function Curve Plots Cardiac Function against Right Atrial Pressure
    • Increasing Preload Increases the Stroke Volume, Increasing Afterload Decreases It
    • Positive Inotropic Agents Shift the Cardiac Function Curve Up and to the Left
    • Fick’s Principle Estimates Cardiac Output from O2 Consumption
    • Cardiac Output can be Determined by the Indicator Dilution Method
    • The Thermal Dilution Method
    • Summary
    • Review Questions
  • Problem Set 5. 2. Cardiac Work
    • Publisher Summary
  • 5. 9. Vascular Function: Hemodynamics
    • Abstract
    • The Vascular System Distributes Cardiac Output to the Tissues
    • The Circulatory System Uses Four Major Physical Principles
    • Flow is Driven by a Pressure Difference
    • Compliance Describes the Relation between Pressure and Volume in the Vessels
    • The Heart’s Ejection of Blood into the Arterial Tree Causes the Arterial Pressure Pulse
    • The Pulse Pressure Depends on the Stroke Volume and Compliance of the Arteries
    • Diastolic Pressure Plus One-Third Pulse Pressure Estimates the Mean Arterial Pressure
    • Pressure and Flow Waves Propagate Down the Arterial Tree
    • Clinicians Use a Sphygmomanometer to Measure Blood Pressure
    • Blood Vessels Branch Extensively, Reducing Their Diameter but Increasing the Overall Area
    • The Major Pressure Drop in the Arterial Circulation Occurs in the Arterioles
    • Poiseuille’s Law Only Approximately Describes Flow in the Vasculature
    • The Ratio of ΔP to Qv Defines the Vascular Resistance
    • Summary
    • Review Questions
  • 5. 10. The Microcirculation and Solute Exchange
    • Abstract
    • The Exchange Vessels Include Capillaries, Terminal Arterioles, and Venules
    • Ultrastructural Studies Reveal Three Distinct Types of Capillaries
    • Capillary Exchange Uses Passive Mechanisms
    • Passive Diffusion Obeys Fick’s Law of Diffusion Across Multiple Barriers
    • Either Flow or Diffusion Can Limit Delivery of Materials to Cells
    • The Interstitial Fluid Concentration Is Set by the Balance Between Consumption and Delivery
    • Regulation of Perfusion Regulates Solute Transfer
    • Some Macromolecules Cross the Capillary Wall by Transcytosis
    • Starling First Described the Forces That Drive Bulk Fluid Movement Across Capillaries
    • In Most Organs, Net Filtration Pressure Drives Fluid Out of the Capillaries at the Arteriolar End
    • The Lymphatics Drain the Fluid Filtered Through the Capillaries Back into the Blood
    • Muscle Activity Helps Pump Lymph Through the Lymphatics
    • Summary
    • Review Questions
  • 5. 11. Regulation of Perfusion
    • Abstract
    • For Any Given Input Pressure, the Caliber of the Arterioles Controls Perfusion of a Tissue
    • Vasoconstriction Decreases Capillary Pressure
    • Vascular Smooth Muscle Contracts by Activation of Myosin Light Chain Kinase
    • Multiple Signals Regulate the Activity of MLCK and MLCP
    • Multiple Mechanisms Cause Vasodilation
    • Control of Blood Vessel Caliber Is Local (Intrinsic) and Systemic (Extrinsic)
    • The Myogenic Response Arises from the Contractile Response to Stretch
    • Endothelial Secretions Dilate Arterioles
    • Metabolic Products Generally Vasodilate
    • Paracrine Secretions Affect Vascular Caliber
    • The Sympathetic Nervous System Predominantly Controls the Vascular System
    • Circulating Hormones That Affect Vessel Caliber Include Epinephrine, Angiotensin, ANP, and Vasopressin
    • Summary
    • Review Questions
  • 5. 12. Integration of Cardiac Output and Venous Return
    • Abstract
    • The Cardiovascular System Is Closed
    • The Cardiovascular System Can Be Simplified for Analysis
    • The Operating Point of the Cardiovascular System Matches Cardiac Function to Vascular Function
    • The Mean Systemic Pressure Normally Equals the Mean Circulatory Pressure
    • Filling the Empty Circulatory System Reveals Stressed and Unstressed Volumes
    • The Vascular Function Curve Can Be Derived from Arterial and Venous Compliances and TPR
    • The Experimentally Determined Vascular Function Curve Follows the Theoretical Result Only for Positive Right Atrial Pressures
    • Simultaneous Solution of the Cardiac Function Curve and Vascular Function Curve Defines the Steady-State Operating Point of the Cardiovascular System
    • Changing Arteriolar Resistance Rotates the Vascular Function Around PMS
    • Changes in Blood Volume Shift the Vascular Function Curve Vertically
    • Changes in the Cardiac Function Curve Change the Steady-State Operating Point
    • Strenuous Exercise Alters Multiple Parts of the Cardiovascular System
    • Summary
    • Review Questions
  • 5. 13. Regulation of Arterial Pressure
    • Abstract
    • Arterial Pressure Drives Flow but Arterial Pressure also Arisesfrom Flow
    • Regulation of Arterial Pressure Occurs on Three Separate Timescales Involving Three Distinct Types of Mechanisms
    • Baroreceptors in the Carotid Sinus and Aortic Arch Sense Blood Pressure
    • The Baroreflex Regulates Heart and Vasculature to Stabilize Blood Pressure
    • The Baroreflex Mediates Parasympathetic and Sympathetic Output from Centers Located in the Medulla
    • Inspiration Infl

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