Quantitative Human Physiology

Preface

Acknowledgments

UNIT 1. Physical and Chemical Foundations of Physiology

1.1. The Core Principles of Physiology

Human Physiology Is the Integrated Study of the Normal Function of the Human Body

Cells Are the Organizational Unit of Life

The Concept of Homeostasis Is a Central Theme of Physiology

The Body Consists of Causal Mechanisms That Obey the Laws of Physics and Chemistry

Evolution Is an Efficient Cause of the Human Body Working Over Long Time Scales

Living Beings Transform Energy and Matter

Function Follows Form

Coordinated Command and Control Requires Signaling at All Levels of Organization

Physiology Is a Quantitative Science

Summary

Review Questions

1.2. Physical Foundations of Physiology I

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

1.3. Physical Foundations of Physiology II

Coulomb’s Law Describes Electrical Forces

The Electric Potential Is the Work per Unit Charge

The Idea of Potential Is Limited to Conservative Forces

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 Make a Current and a Solute Flux

The Relation Between J and C Defines an Average Velocity

Summary

Review Questions

Problem Set 1.1. Physical Foundations

1.4. Chemical Foundations of Physiology I

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

Water Provides an Example of a Polar Bond

Intermolecular Forces Arise from Electrostatic Interactions

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

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

The Michaelis–Menten Formulation of Enzyme Kinetics

Summary

Review Questions

Appendix 1.5.A1 Transition State Theory Explains Reaction Rates in Terms of An Activation Energy

The Activation Energy Depends on the Path

1.6. Diffusion

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

1.7. Electrochemical Potential and Free Energy

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

Quantitative Human Physiology: An Introduction presents a course in quantitative physiology developed for undergraduate students of Biomedical Engineering at Virginia Commonwealth University. The text covers all the elements of physiology in nine units: (1) physical and chemical foundations; (2) cell physiology; (3) excitable tissue physiology; (4) neurophysiology; (5) cardiovascular physiology; (6) respiratory physiology; (7) renal physiology; (8) gastrointestinal physiology; and (9) endocrinology. The text makes extensive use of mathematics at the level of calculus and elementary differential equations. Examples and problem sets are provided to facilitate quantitative and analytic understanding, while the clinical applications scattered throughout the text illustrate the rationale behind the topics discussed. This text is written for students with no knowledge of physiology but with a solid background in calculus with elementary differential equations. The text is also useful for instructors with less time; each chapter is intended to be a single lecture and can be read in a single sitting.

• A quantitative approach that includes physical and chemical principles
• An integrated approach from first principles, integrating anatomy, molecular biology, biochemistry and physiology. Illustration program reinforces the integrated nature of physiological systems
• Pedagogically rich, including chapter objectives, chapter summaries, large number of illustrations, and short chapters suitable for single lectures
• Clinical applications relevant to the biomedical engineering student (TENS, cochlear implants, blood substitutes, etc.)
• Problem sets provide opportunity for practice and assessment throughout the course.

Undergraduate bioengineering students