Principles of Biological Regulation: An Introduction to Feedback Systems presents some understanding of control, regulatory, and feedback mechanisms in biological systems. This book discusses concepts related to the dynamic behavior of both individual biological processes and systems of processes that make up an organism. Comprised of 10 chapters, the book also describes the characteristics of biological feedback systems, focusing on the physical concepts. After briefly dealing with involved regulatory processes in biological systems, the book goes on discussing the flow or transport of material through a series of processes in the steady-state. Next chapter uses superposition principle to explain the changes that biological systems undergo following a disturbance or under dynamic behavior. The subsequent chapters cover the fundamental principles of negative biological feedback and to the effects it produces both under steady-state and dynamic behavior. Other chapters describe the effect of sinusoid signals on biological processes and present some stability criteria applied to technological systems and also their value in the study of homeostatic processes. The book also discusses some aspects of homeostats that seem to distinguish them from technological feedback systems. These features include not only the components themselves and their organization, but also the experimental problems involved in their study. The concluding chapters describe nonlinear behavior with great relevance to homeostatic systems and rate processes (production or destruction) for which the roles of stimulus and initial conditions are different. Mathematical relations developed from the conservation of mass and the mass action for chemical reactions are also presented. The book is an invaluable resource for life scientists and researchers.

Table of Contents:
PrefaceAcknowledgments1. Regulatory Processes in Biological Systems 1.1 Biology as a Science of Organization 1.2 Regulatory Biology 1.3 Historical Development 1.4 Epitome References2. Flow Processes in the Steady State 2.1 Introduction 2.2 Cellular Diffusion of CO2 2.3 Heat Flow in a Muscle; Definition of a Compartment 2.4 Flow through a Compartment: the Storage Function 2.5 Loss Functions 2.6 Single-Compartment Process in the Steady State 2.7 Factors Affecting the Steady State; Variables and Parameters 2.8 Multicompartment Systems; Noninteracting Processes 2.9 Interacting Processes 2.10 Aqueous Flow through the Eye; Two-Compartment Model 2.11 Disturbances to the Steady State 2.12 Transmission Function, Gain 2.13 Flow Graphs and Block Diagrams 2.14 Glucose Transport with Intravenous Feeding 2.15 Steady-State Control of the Extraoculär Muscles 2.16 Mathematical Treatment of the Steady State 2.17 Glands as Transducers; Biological Fluxes 2.18 Epitome Problems References3. Dynamic Behavior; the Transient Response 3.1 Introduction 3.2 Compartment Filling at a Prescribed Rate; No Losses 3.3 Compartment Emptying 3.4 Properties of the Exponential Curve 3.5 Single Compartment; Transient and Steady-State Solution 3.6 First-Order Dynamics 3.7 Second-Order System; Noninteracting Processes 3.8 Noninteracting and Interacting Processes 3.9 Signal Transmission through Several Compartments 3.10 Second-Order Transient; Oscillatory Case 3.11 Oscillations in Limb Movement, Dysmetria 3.12 Systems of Higher Order 3.13 Modes of Free Vibration 3.14 Block Diagram Symbols for First-Order Processes 3.15 Responses to Pulse Disturbances 3.16 Muscle Dynamics 3.17 Mathematical Analysis of Linear Dynamical Systems 3.18 Epitome Problems References4. Introduction to Feedback; the Steady State 4.1 Introduction 4.2 Feedback in a Two-Compartment System 4.3 The Steady-State Operating Point; Definition of a Negative Feedback System 4.4 Effect of Disturbances upon the Operating Point 4.5 Open-Loop and Closed-Loop Gain 4.6 The Control Mechanism; Reference Input and Sign Reversal 4.7 Further Discussion of Loop Gain 4.8 Reducing the Effects of Disturbances 4.9 Effect of Loop Gain on Perturbations; Sensitivity 4.10 Further Aspects of Sensitivity 4.11 Operating Point, Reference Input, and Summing Point in Nonlinear Systems 4.12 The Error Concept 4.13 Temperature Regulation under Heat Stress; Sweating 4.14 Regulation of Thyroxine; the Thyroid-Pituitary System 4.15 Types of Regulator; the Servomechanism 4.16 Steady-State Relations in a Type 1 System 4.17 Mechanisms of Sign Reversal 4.18 Generalized Block Diagram 4.19 Blood Pressure Regulation 4.20 The Stretch Reflex 4.21 Epitome Problems References5. Feedback Systems; Dynamic Behavior 5.1 Introduction 5.2 Changes in the System Behavior with Feedback 5.3 Block Diagrams; Open- and Closed-Loop Behavior 5.4 First-Order Systems; Change in the Operating Point 5.5 Types of Disturbances; System Trajectory 5.6 Second-Order System; Responses to an Input Disturbance 5.7 Second-Order System; Parametric Disturbance 5.8 The Complex s-Plane; Pole Location and Transient Response 5.9 Second-Order Systems; Poles on the s-Plane 5.10 Complex Poles; Damped Oscillatory Modes 5.11 Second-Order System; Effect of Increased Gain 5.12 Signal Transmission through a Feedback System Having an Oscillatory Response 5.13 Effect of Time Constant Ratio on the Transient Modes 5.14 Oscillations in Neuromuscular Control 5.15 Baroreceptor Reflex 5.16 Further Discussion of Feedback System Dynamics 5.17 Epitome Problems References6. Sinusoidal Signals 6.1 Introduction 6.2 Properties of a Sinusoid 6.3 Sinusoidal Transmission; First-Order Process 6.4 Sinusoidal Response of a Single Compartment at Different Frequencies 6.5 Sinusoidal Modulation 6.6 Frequency Spectrum; First-Order Process 6.7 Logarithmic Coordinates 6.8 Frequency Spectrum of a Second-Order System 6.9 Sign Inversion and Its Frequency Spectrum 6.10 Open-Loop Frequency Spectrum 6.11 Effect of Loop Gain on the Open-Loop Spectrum 6.12 Frequency Spectrum; Nerve-Muscle Preparation 6.13 Frequency Spectrum; the Wolf Spider Eye 6.14 Transmission of a Periodic Signal 6.15 Development of the Fourier Transform 6.16 System Analysis with the Fourier Transform 6.17 Properties of the Baroreceptor 6.18 Spectra of the Stretch Reflex 6.19 Open- and Closed-Loop Frequency Spectra 6.20 Resonance in a Second-Order Feedback System 6.21 Algebra of Complex Numbers 6.22 Further Discussion of Sinusoidal Signals and Frequency Spectra 6.23 Epitome Problems References7. Stability 7.1 Introduction 7.2 Instability in a Liquid Level Regulator 7.3 Transients in a Third-Order Feedback System; Critical Gain 7.4 Stability and the Sinusoidal Domain 7.5 Nystagmus; an Example of Physiological Instability 7.6 Factors Contributing to Instability; Stability Boundaries 7.7 Stability Criteria in the Time Domain 7.8 Ideal Transport Lag 7.9 Feedback System Having Transport Lag 7.10 Stability Boundary for a First-Order Process With Transport Lag 7.11 Loop Gain of the Pupil Reflex Arc 7.12 Polar Plots; the Blood Pressure Regulator 7.13 Further Discussion of Stability 7.14 Epitome Problems References8. Distinctive Features of Homeostatic Systems 8.1 Introduction 8.2 Temperature Regulation; Circumstantial Evidence 8.3 Temperature Regulating Mechanisms in Man 8.4 Temperature Receptors 8.5 The Regulated Variable 8.6 Body Temperature Regulation by Sweating 8.7 Shivering 8.8 Sign Reversal; Control of Loss Functions 8.9 Multivariable System 8.10 Steady-State Changes in the Operating Point; Effect of Set Point Changes and Disturbances 8.11 Measurement of Open-Loop Gain 8.12 Regulation of the Ca Concentration in Blood Plasma 8.13 Diffusion Processes in the Steady State 8.14 Dynamic Characteristics of the Diffusion Process 8.15 Homeostats and Power Supply Dynamics 8.16 Adaptation and Adjustments in Homeostats 8.17 Disturbances to Biological Systems 8.18 Further Discussion of Physiological Signals and System Complexity 8.19 Epitome Problems References9. Nonlinear Systems 9.1 Introduction 9.2 Linear versus Nonlinear Behavior 9.3 Superposition of Responses 9.4 Steady-State Characteristic; Threshold and Saturation 9.5 Multiple Operating Points; Steady-State Stability 9.6 Switching Action 9.7 Two-Position Control of a Feedback System 9.8 Some Characteristics of a Two-Position Regulator 9.9 Process Sequence 9.10 Variable Parameter System; Facultative Process 9.11 Phase Plane Representation of System Dynamics 9.12 The Linear System as an Oscillator 9.13 Relaxation Oscillator 9.14 Asymmetrical Dynamic Behavior 9.15 Further Discussion of Nonlinear Phenomena 9.16 Epitome Problems References10. Biochemical Control 10.1 Introduction 10.2 Reversible First-Order Chemical Reaction 10.3 Open Systems 10.4 Enzyme-Controlled Reaction; the Michaelis-Menton Equations 10.5 Rate-Controlling Processes 10.6 Dynamics of the Michaelis-Menton Equations 10.7 Feedback Control by Competitive Inhibition 10.8 Allosteric Enzymes 10.9 Repression and Induction of Enzyme Synthesis 10.10 Regulation of L-Isoleucine Synthesis 10.11 Regulatory Mechanisms in the Synthesis of Amino Acids 10.12 Some General Observations on Biochemical Control 10.13 Epitome Problems ReferencesIndex