
Quantitative Human Physiology
An Introduction
Resources
Description
Key Features
- 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.
Readership
Undergraduate bioengineering students
Table of Contents
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<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
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
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
2.2. DNA and Protein Synthesis
DNA Makes Up the Genome
DNA Consists of Two Intertwined Sequences of Nucleotides
RNA Is Closely Related to DNA
Messenger RNA Carries the Instructions for Making Proteins
Ribosomal RNA Is Assembled in the Nucleolus from a DNA Template
Transfer RNA Covalently Binds Amino Acids and Recognizes Specific Regions of mRNA
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
Summary
Review Questions
2.3. Protein Structure
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
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
Other Lipid Components of Membranes Include Cardiolipin, Sphingolipids, and Cholesterol
Phospholipids in Water Self-Organize into Layered Structures
Surface Tension of Water Results from Asymmetric Forces at the Interface
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
Lipids Maintain Dynamic Motion within the Bilayer
Lipid Rafts Are Special Areas of Lipid and Protein Composition
Membrane Proteins Bind to Membranes with Varying Affinity
Secreted Proteins Have Special Mechanisms for Getting Inside the Endoplasmic Reticulum
Summary
Review Questions
Problem Set 2.1. Surface Tension, Membrane Structure, Microscopic Resolution, and Cell Fractionation
2.5. Passive Transport and Facilitated Diffusion
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
Water Moves Passively Through Aquaporins
Summary
Review Questions
2.6. Active Transport
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
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
2.7. Osmosis and Osmotic Pressure
The Model for Water Transport Is a Microporous Membrane
Case A: The Solute Is Very Small Compared to the Pore
Case B: The Solute Is Larger than the Pore: Osmosis
The van’t Hoff Equation Relates Osmotic Pressure to Concentration
The Osmotic Coefficient Corrects for NonIdeal Behavior of Solutions
Osmosis in a Microporous Membrane Is Caused by a Momentum Deficit within the Pores
The Flow across a Membrane Responds to the Net Hydrostatic and Osmotic Pressure
Case C: The Solute is Smaller than the Pore but is not Tiny Compared to the Pore
Solutions May Be Hypertonic or Hypotonic
Osmosis, Osmotic Pressure, and Tonicity Are Related but Distinct Concepts
Osmotic Pressure Is a Property of Solutions Related to Other Colligative Properties
Cells Behave Like Osmometers
Cells Actively Regulate their Volume through RVDs and RVIs
Summary
Review Questions
Appendix 2.7.A.1 Thermodynamic Derivation of van’t Hoff’s Law
Appendix 2.7.A2 Mechanism of Osmosis across a Microporous Membrane
Problem Set 2.2. Membrane Transport
2.8. Cell Signaling
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 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
Take a Global View of Metabolism
Energy Production and use in the Cell is Analogous to Societal Production and use of Electrical Power
Energy Production Occurs in Three Stages: Breakdown into Units, Formation of Acetyl CoA and Complete Oxidation of Acetyl CoA
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-1-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
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 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
Oxidative Phosphorylation Couples Inward H+ Flux to ATP Synthesis
The Proton Electrochemical Gradient Provides the Energy for ATP Synthesis
NADH Forms 3 ATP Molecules; FADH2 Forms 2 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
Fats and Proteins Contribute 60% 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
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
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
Voltage-Dependent Changes in Ion Conductance Cause the Action Potential
Conductance Depends on the Number and State of the Channels
Patch Clamp Experiments Measure Unitary Conductances
Summary
Review Questions
Appendix 3.2.A1 The Hodgkin–Huxley Model of the Action Potential
3.3. Propagation of the Action Potential
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
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
Problem Set 3.1. Membrane Potential, Action Potential, and Nerve Conduction
3.4. Skeletal Muscle Mechanics
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
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
Introduction
Muscle Cells 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
Cross-Bridges from the Thick Filament Split ATP and Generate Force
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
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
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
3.7. Muscle Energetics, Fatigue, and Training
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
In Maximum Effort, There Is No Rest Phase
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 Is the Preferred Fuel for Muscle
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
Early and Rapid Strength Gains Comes from Training the Brain
Strength Training Induces Muscle Hypertrophy
Hormones Influence Muscle Size (=Strength)
Myostatin Is a Negative Regulator of the Muscle Mass
Endurance Training Uses Repetitive Movements to Tune Muscle Metabolism
Our 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
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 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
Activation of Beta2 Receptors on Smooth Muscle Causes Relaxation by Removing 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
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
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
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
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
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
4.6. The Chemical Senses
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
Olfactory Output Connects Directly to the Cortex in the Temporal Lobe
A Second Olfactory Output Is Through the Thalamus to the Orbitofrontal Cortex
A Third Pathway of Olfactory Sensors Is Between the Vomeronasal Organ and the Hypothalamus
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
Some Odorants Do Not Use Golf Linked to Odorant Binding Proteins
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 Is 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
Summary
Review Questions
4.7. Hearing
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
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
Problem Set 4.2. Sensory Transduction
4.9. Autonomic Nervous System
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 Muscarinic Receptors
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
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
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
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
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
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
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
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
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
5.9. Vascular Function
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
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
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
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
Arterial Pressure Drives Flow but Arterial Pressure also Arises from 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 Influences Heart Rate—The Respiratory Sinus Arrhythmia
Higher Centers Influence Blood Pressure and Heart Rate
Long-Term Regulation of Blood Volume Determines Long-Term Regulation of Blood Pressure
Sympathetic Tetralogy
Hormonal Regulation of Blood Pressure
Summary
Review Questions
Problem Set 5.3. Hemodynamics and Microcirculation
UNIT 6. Respiratory Physiology
6.1. The Mechanics of Breathing
The Respiratory System Supplies O2 and Removes Waste CO2
Four Core Aspects of Respiratory Physiology
Air Flows Through an Extensive Airway System That Filters, Warms, and Humidifies the Air
Gas Flows in Response to Pressure Differences
Changes in Lung Volumes Produce the Pressure Differences That Drive Air Movement
Skeletal Muscles Power Inspiration
Resting Expiration Is Passive; Abdominal Muscles Aid in Forceful Expiration
The Pleura and the Pleural Fluid Join the Lungs to the Chest Wall
Compliance Measures the Ease of Expanding the Lungs
The Compliance and Recoil Tendency of the Lung Is Produced by Elastic Fibers and by Surface Tension
The Law of Laplace Predicts Alveolar Instability
Pulmonary Surfactant Lowers the Surface Tension in the Alveoli
The Lungs and Chest Wall Interact to Produce the Pressures That Drive Ventilation
Breaking the Seal on the Intrapleural Space Collapses the Lungs
Airway Resistance Partly Determines Dynamic Pressures
Summary
Review Questions
6.2. Lung Volumes and Airway Resistance
Spirometers Measure Lung Volumes and Allow Identification of Several Lung Volumes and Lung Capacities
Lung Capacities Are Combinations of Two or More Lung Volumes
Lung Volumes and Capacities Vary Mainly with Body Size
Pulmonary Ventilation Is the Product of Respiratory Rate and TV
During Exercise, Pulmonary Ventilation Increases Due to Increased RR and TV
The Maximum Voluntary Ventilation Exceeds Pulmonary Ventilation During Exercise
Spirometry Also Provides a Clinically Useful Measure of Airway Resistance
Airway Resistance Depends on Whether Airflow Is Laminar or Turbulent
The Poiseuille Equation Derived for Right Cylinders Does Not Model the Complicated Airways
Airway Resistance Is the Slope Between ΔP and QV
Turbulent and Laminar Flow Result in Resistances That Occur in Series and Add
Airway Resistance Depends on Lung Volume
Dynamic Compression of the Airways During Forceful Expiration Limits Airflow
Airway Resistance Is Modified by Smooth Muscle Contraction of the Airways
Summary
Review Questions
6.3. Gas Exchange in the Lungs
The Respiratory System Exchanges Blood Gases with Atmospheric Gases
The Partial Pressure of a Gas Is its Mole Fraction Times the Total Pressure
The Vapor Pressure Is the Partial Pressure of Water in the Gas Phase That Is in Equilibrium with Liquid Water
The Vapor Pressure at Body Temperature is 47 mmHg
Henry’s Law Describes the Dissolution of Gases in Water
Conversion of Partial Pressures and Volumes at STPD to Those at BTPS
Gases Diffuse Across the Alveolar Membrane Passively
The Diffusing Capacity Is the Flow Per Unit Partial Pressure
The Anatomic Dead Space Reduces the Volume of Inspired Air That Exchanges with the Blood
Physiologic Dead Space Is Larger than the Anatomic Dead Space
The Rate of CO2 Production Allows Calculation of Alveolar Ventilation
The Alveolar Gas Equation Allows Calculation of
Blood Is in the Lungs for Less than a Second—But That Is Long Enough to Equilibrate the Gases
Blood Flow to the Lung Varies with Position with Respect to Gravity
Regulation of the Pulmonary Circulation Helps Restore the Ventilation/Perfusion Ratio
Summary
Review Questions
Appendix 6.3.A1 Derivation of the Steady-State Gas Exchange Equations
Appendix 6.3.A2 Conversion of Partial Pressures and Volumes Between STPD and BTPS
Problem Set 6.1. Airway Resistance and Alveolar Gas Exchange
6.4. Oxygen and Carbon Dioxide Transport
Dissolved Oxygen Content of Blood Is Small
Most Oxygen in Blood Is Bound to Hemoglobin
Oxygen Consumption Can Be Calculated by Blood Flow Times the A–V Difference in Oxygen
Oxygen Consumption Can Be Calculated from the Difference between O2 Inspired and O2 Expired
O2 Diffuses from Blood to the Interstitial Fluids and Then to the Cells
Hemoglobin Delivers Oxygen to the Tissues
Myoglobin Stores O2 in Oxidative Muscle and May Enhance Diffusion
Shift of the O2 Dissociation Curve to the Right Helps Deliver O2 to Exercising Muscles
Increased O2 Delivery in Exercise Is Caused by Increased Blood Flow and Shorter Diffusion
Dissolved CO2 Accounts for a Small Fraction of Blood CO2 Transport
Most CO2 Is Carried in the Blood as HCO3−
Carbaminohemoglobin Accounts for a Small Fraction of Transported CO2
Summary
Review Questions
6.5. Acid–Base Physiology I
pH Is a Monotonically Decreasing Function of [H+]
Plasma pH is Maintained within Narrow Limits
The Body Uses Chemical Buffers, the Respiratory System, and the Renal System to Regulate pH
Chemical Buffers Absorb or Desorb H+ According to the Law of Mass Action
The Isohydric Principle States that All Buffers in a Solution Are in Equilibrium with the Same [H+]
Expressing [H2CO3] in Terms of PCO2 Makes the Henderson–Hasselbalch Equation More Useful
The Respiratory System Regulates pH by Adjusting Plasma PCO2
Hypoventilation in Response to Alkalosis is Called Respiratory Compensation of Alkalosis
Hyperventilation in Response to Acidosis is Called Respiratory Compensation of Acidosis
Respiratory Acidosis and Respiratory Alkalosis
The pH–HCO3− Diagram Depicts Acid–Base Balance Graphically
Summary
Review Questions
6.6. Control of Ventilation
Nerves Regulate Breathing
Control of Breathing Involves Voluntary and Involuntary Components
The Brain stem Contains a Pontine Respiratory Group in the Pons, an Apneustic Center in the Lower Pons, and Dorsal and Ventral Respiratory Groups in the Medulla
The DRG Receives a Variety of Inputs and Excites Inspiratory Motor neurons
The VRG Contains Both I and E Neurons
Despite Progress, the Neural Mechanism of the Respiratory Pattern Remains Unknown
Peripheral Chemosensors Modulate Respiration in Response to Changes in PaO2, PaCO2, and pH
Peripheral Arterial Chemosensors Increase Firing Rates with Increased PaCO2, Decreased pH, and Decreased PaO2
Peripheral Chemosensors for PaO2 are More Important than those for PaCO2
The Ventilatory Response to Increased Chemoreceptor Firing Rate Is Increased Ventilation
Central Chemosensors Provide the Major Response to Changes in PaCO2
The Brain Adjusts the [HCO3−] of the CSF
Ventilatory Drive Increases by Integrated Response to Elevated PaCO2, Metabolic Acidosis, or Hypoxia
Airway and Lung Mechanoreceptors Alter Breathing Patterns
Increased Respiration during Exercise May be Neural and May Involve Learning
Summary
Review Questions
Problem Set 6.2. Gas Transport and pH Disturbances
UNIT 7. Renal Physiology
7.1. Body Fluid Compartments
Fick’s Dilution Principle Allows Determination of Body Fluid Compartments
Inulin Marks the Extracellular Fluid; Evans’ Blue Dye Marks Plasma
The Main Fluid Compartments Are the Intracellular Compartment, the Interstitial Compartment, and the Plasma
The TBW Varies with Body Composition
Water Composition of the LBM Varies with Age and Sex
The Fluid Compartments Correspond to Anatomic Compartments
Body Fluids Obey the Principle of Macroscopic Electroneutrality
The Gibbs–Donnan Equilibrium Arises from Unequal Distribution of Imperant Ions
Changes of Plasma Volume and Composition Transfer to all Fluid Compartments
Darrow–Yannet Diagrams Depict Fluid Compartment Composition and Volume
The Kidneys Regulate Body Fluid Volume and Composition by Acting on the Plasma
Summary
Review Questions
7.2. Functional Anatomy of the Kidneys and Overview of Kidney Function
Function Follows form in Functional Units Called Nephrons
The Paired Kidneys Have an Enormous Blood Supply and Drain Urine into the Bladder through the Ureters
Intermediate Level of Kidney Structure Reveals Functional Areas
The Renal Arteries Arise from the Abdominal Aorta
The Functional Unit of the Kidney, the Nephron, Participates in all Elementary Renal Processes
The Nephron Is a Tubule with Functionally and Microscopically Distinct Regions
The Juxtaglomerular Apparatus Produces Renin
Nonexcretory Functions of the Kidney
Summary
Review Questions
7.3. Glomerular Filtration
Morphological Studies First Led to the Idea of Glomerular Filtration
Micropuncture Studies Showed That the Fluid in Bowman’s Space Is an Ultrafiltrate
Tubular Reabsorption Explains the Lack of Nutrients in the Final Urine
Tubular Secretion Adds Material to the Ultrafiltrate
The Three Elementary Nephron Processes Are Ultrafiltration, Reabsorption, and Secretion
The Clearance of Inulin Provides an Estimate of the Glomerular Filtration Rate
The Clearance of Para Amino Hippuric Acid Allows Estimation of Renal Plasma Flow
The Clearance of a Substance Depends on How It Is Handled by the Kidney
Glomerular Filtration Is Like a Leaky Hose; about 20% of the Plasma Constituents End Up in the Filtrate
Multiple Structures Contribute to the Selectivity of the Glomerular Filtrate
The Endothelial Cell Layer Retains the Cellular Elements of Blood
The Basement Membrane Excludes Some Proteins
The Slit Membrane Retains Proteins 70 kDa or Larger
The Sieving Coefficient Depends Mainly on the Slit Diaphragm
The Glomerulus Selectively Excludes Proteins Based on Size and Charge
The Starling Forces Drive Ultrafiltration
Summary
Review Questions
Problem Set 7.1. Fluid Volumes, Glomerular Filtration, and Clearance
7.4. Tubular Reabsorption and Secretion
The Filtered Load of Water and Valuable Nutrients Is Enormous
The Renal Titration Curve of Inulin Is Linear
The Renal Titration of Glucose Shows Reabsorption and Saturation Kinetics
Saturation Kinetics and Nephron Heterogeneity Causes Splay
High Plasma Glucose in Diabetes Mellitus Causes Glucose Excretion
The Kidneys Help Regulate Plasma Phosphate
Renal Titration Curve of PAH Shows Secretion
The Meaning of the Clearance Depends on the Renal Handling
Endogenous Creatinine Clearance Approximates the GFR
Plasma Creatinine Concentration Alone Indicates the GFR
(TF/P)inulin Marks Water Reabsorption
The Double Ratio (TF/P)x/(TF/P)inulin is the Fraction of the Filtered Load of x Remaining
Micropuncture Studies Show that the Proximal Tubule Reabsorbs Two-Thirds of the Ultrafiltrate
The Proximal Convoluted Tubule Contains Many Transport Mechanisms
Absorption of Water and Salt across the Late Proximal Tubule
Summary
Review Questions
7.5. Mechanism of Concentration and Dilution of Urine
Life on Dry Land Struggles Against Desiccation
Control of Urine Concentration Uses an Osmotic Gradient and Regulated Water Permeability
Tubular Transport Mechanisms Differ Along the Length of the Nephron
The Vasa Recta Are Counter-Current Exchangers
Urea Contributes to the Osmotic Gradient in the Inner Medulla
Transport by the Vasa Recta Is Essential to the Operation of the Loop of Henle
Increased Solute Loads in the Distal Nephron Produce an Osmotic Diuresis
ADH Controls Distal Nephron Permeability
Summary
Review Questions
7.6. Regulation of Fluid and Electrolyte Balance
Regulation of Glomerular Filtration Rate Affects Urine Output
RBF and GFR Exhibit Autoregulation
The Nephron Adjusts Reabsorption of Water and Salt to Match Changes in the GFR
Water Balance in the Body Is Mediated by Antidiuretic Hormone
ADH Secretion by the Brain Is Increased by Hypovolemia and Hyperosmolarity
ADH Increases Water Permeability of the Distal Nephron
The ADH-Renal System Forms Negative Feedback Loops
Regulation of Na+ Balance Involves the Renin–Angiotensin–Aldosterone System
Atrial Natriuretic Peptide and Endogenous Digitalis-Like Substance Increases Na+ Excretion in Hypervolemia
The Integrated Response to Decreased Blood Volume
Integrated Response to Increased Na+ Load or Volume Expansion
Summary
Review Questions
7.7. Renal Component of Acid–Base Balance
The Kidneys Eliminate the Acid Produced from Metabolism
The Body Uses Chemical Buffers, the Respiratory System, and the Renal System to Regulate pH
Acid Excretion by the Tubule Adjusts Blood pH
The Kidney Links Acid Secretion to HCO3− Appearance in Plasma
Secreted Acid Reclaims HCO3− or Combines with Titratable Acid or Ammonium
Ammonia Does not Show up as Titratable Acid because its pK is too High
New HCO3− Formed Is the Sum of Titratable Acid and NH4+ Minus the Excreted HCO3−
Ammonium Originates from Amino Acids in Proximal Tubule Cells
The Thick Ascending Limb Secretes Acid, Reabsorbs Bicarbonate and Ammonium
Ion Transport in the Distal Nephron and Collecting Duct Show Reciprocal Relations between K+ and H+ Secretion and HCO3− and Cl− Secretion
Tubular pH and Cellular Regulate HCO3− Reabsorption and H+ Secretion
Excretion of NH4+ Increases with Chronic Acidosis
The Kidneys Compensate for Respiratory Acidosis by Increasing [HCO3−]
The Kidneys Compensate for Respiratory Alkalosis by Decreasing [HCO3−]
The Overall Response to Metabolic Acidosis Involves Both Lungs and Kidneys
The Overall Response to Metabolic Alkalosis Involves Both Lungs and Kidneys
The Overall Picture
Summary
Review Questions
Problem Set 7.2. Fluid and Electrolyte Balance and Acid–Base Balance
UNIT 8. Gastrointestinal Physiology
8.1. Mouth and Esophagus
The Gastrointestinal System Secures Nutrients for Maintenance, Movement, and Growth
The Gastrointestinal System Is a Tube Running from Mouth to Anus
The Gastrointestinal System Propels Material between Defined Areas Demarcated by Sphincters
The Liver and Pancreas Secrete Materials into the Intestine to Aid Digestion and Absorption
Chewing Begins Digestion
Chewing Has Multiple Purposes
Saliva Moistens, Lubricates, Digests, and Protects
Salivary Glands Produce an Isotonic Fluid that Is Subsequently Modified
Saliva Composition Depends on the Flow Rate
Parasympathetic Stimulation Results in High-Volume, Watery Saliva
Na+ and Cl− are Reabsorbed in the Salivary Ducts, and K+ and HCO3− are Secreted
The Salivary Nuclei of the Medulla Control Salivation
A Swallowing Center in the Medulla Orchestrates Swallowing
Swallowing Is a Complex Sequence of Events
Swallowing Consists of a Pharyngeal Phase and an Esophageal Phase
The Esophagus Contains an Inner Circular Smooth Muscle Layer and an Outer Longitudinal Smooth Muscle Layer
The Gut Contains Two Ganglionic Plexuses of Nerve Cells, the Body’s “Little Brain”
The LES Must Relax for Food to Enter the Stomach
Summary
Review Questions
8.2. The Stomach
The Stomach Stores Food and Releases it Gradually to the Small Intestine
The Stomach Has Distinct Regions
Extrinsic and Intrinsic Nerves Control Gastric Motility
The Orad Stomach Relaxes to Accommodate Large Meals
Pacemaker Cells along the Greater Curvature Determine Stomach Motility after a Meal
Gastric Contractions Result in Propulsion, Grinding, or Retropulsion of Stomach Contents
Stomach and Duodenal Contents Regulate Stomach Emptying
Nerves and GI Hormones Alter Stomach Emptying
The Migrating Motility Complex Clears the Stomach and Intestine during Fasting
The Stomach Secretes HCl, Pepsinogen, Mucus, Gastric Lipase, and Intrinsic Factor
Acid Secretion Is Regulated in Three Phases: The Cephalic Phase, Gastric Phase, and Intestinal Phase
The Surface Membrane H+-K+-ATPase, or Proton Pump, Actively Secretes HCl
Summary
Review Questions
8.3. Intestinal and Colonic Motility
The Small Intestine Consists of Duodenum, Jejunum, and Ileum
The Small Intestine Modulates Gastric Emptying
Intrinsic Innervation of the Intestine Consists of the Myenteric Plexus, Submucosal Plexus, and the Interstitial Cells of Cajal
Extrinsic Innervation of the Gut Arises from Parasympathetic and Sympathetic Nerves
Slow Wave Activity Forms the Basis of Intestinal Smooth Muscle Contraction
Intestinal Motility Has Several Different Patterns: Segmentations, Peristalsis, migrating motor complex or migrating myoelectric complex, and Reverse Peristalsis
The Ileocecal Sphincter Prevents Reflux of Colonic Contents into the Ileum
The Large Intestine or Colon Has Several Anatomic Regions
Colonic Motility Shows Several Distinct Patterns
Local and Extrinsic Nervous Innervation Controls Ileal and Colonic Motility
Defecation Involves Voluntary and Involuntary Muscles
Vomiting Removes Potentially Dangerous Material from the Gut
Vomiting Is a Complicated Programmed Event
Summary
Review Questions
8.4. Pancreatic and Biliary Secretion
The Exocrine Pancreas Secretes Digestive Enzymes and HCO3−
The Pancreas Secretes Four Classes of Enzyme
The Pancreas Secretes Inactive Forms of the Proteolytic Enzymes
Pancreatic Amylase Breaks Down Starches
The Pancreas Secretes a Set of Lipolytic Enzymes
The Pancreas Secretes Nucleolytic Enzymes
Pancreatic Duct Cells Secrete an Alkaline Solution
Postprandial Pancreatic Enzyme Secretion Is Regulated in Cephalic, Gastric, and Intestinal Phases
Secretin Primarily Regulates Pancreatic Duct Secretion
The Liver Produces Bile and Stores It in the Gallbladder in the Interdigestive Period
Hepatocytes Are Polarized Cells with Special Access to Plasma
Bile Consists of Bile Acids, Phospholipids, Cholesterol, Bile Pigments, Mucin, Xenochemicals, and Electrolytes
The Liver Makes and Recycles Bile Acids as an Integral Part of Biliary Secretion
The Liver Excretes Xenobiotics (Foreign Biologically Active Chemicals)
ABCG5 and ABCG8 Secrete Cholesterol into the Bile
The Gallbladder Stores and Concentrates Bile and Releases It during Digestion
The Bile Duct Cells Secrete a HCO3−-Rich Solution Much Like Pancreatic Duct Cells
Summary
Review Questions
8.5. Digestion and Absorption of the Macronutrients
The Intestine Increases Its Surface Area by Folds upon Folds
The Intestinal Lining Continuously Renews Itself
Protein Digestion Occurs in a Gastric Phase and an Intestinal Phase
Specific Carriers Move Amino Acids across the Brush Border and BasoLateral Membranes
The Intestinal Peptide Transporter Has Broad Specificity and Cotransports H+
Distinct Carriers Transport Amino Acids across the Basolateral Membrane
Carbohydrates Are Mainly Digested in the Small Intestine
Indigestible Carbohydrates Make Up Part of Dietary Fiber
The Brush Border Completes Starch Digestion
Glucose, Fructose, and Galactose Absorption is Carrier Mediated
Lipid Digestion Begins with Emulsification
Most Lipolytic Activity Occurs in the Small Intestine
Hydrolysis Products of Lipids Are Absorbed and Then Repackaged into Lipoproteins
Bile Acids Are Absorbed in the Terminal Ileum
Summary
Review Questions
8.6. Energy Balance and Regulation of Food Intake
Early Studies on Energy Balance Used Calorimeters
“The Energy Content of Food” Is Its Heat of Combustion
Measurement of Energy Expenditure by Indirect Calorimetry
Indirect Calorimetry and Urinary Nitrogen Allows Estimation of Catabolism of Macronutrients
Energy Expenditure Consists of Basal Metabolism Plus Activity Increment
Empirical Formulas for BMR
Eating Food Increases Metabolism
Activity Adds the Greatest Increment to Metabolism
The Body Homeostatically Regulates Its Weight
The Central Nervous System Regulates Feeding Behavior
Early Studies Showed That the Hypothalamus Drives Feeding Behavior
The Simplistic Early View Is Supplanted by a Picture of Multiple Centers and Multiple Signals
Short-Term Signals Limit the Size of Meals: They Are Satiety Signals
Long-Term Signals Maintain Body Composition: They Are Adiposity Signals
Integrated Mechanism of Food Intake Regulation
Summary
Review Questions
Problem Set 8.1. Energy Balance
UNIT 9. Endocrine Physiology
9.1. General Principles of Endocrinology
Endocrine Glands Release Signaling Molecules into the Blood
Modern Definitions of Hormone Include Local and Distant Effects and Integration of the Endocrine and Neural Systems of Control
The Neural System Provides Fast, Short-Lived Control; Endocrine Control Is Slower and Longer Lasting
Hormones Can Be Classified by Their Chemical Structure and Source
Polypeptide Hormones Are Typically Synthesized as Larger Precursors
Steroid Hormones Are Metabolized from Cholesterol and Are Not Stored
Blood Carries Hormones in Either Free or Bound Forms
Only Target Cells with Receptors to the Hormone Respond to the Hormone
Dose–Response Curves Derive from the Kinetics of Hormone Binding and Post-Receptor Events
Dose–Response Curves Can Be “Upregulated” or “Downregulated”
The Half-Life and Metabolic Clearance Rate Quantitatively Describe Hormone Metabolism
The MCR Is Inversely Related to the Half-Life
A Variety of Techniques Can Measure Hormone Levels
Summary
Review Questions
Appendix 9.1.A1 Analysis of Ligand Binding
9.2. Hypothalamus and Pituitary Gland
The Pituitary Gland Lies Below the Brain and Connects to the Hypothalamus by a Narrow Stalk
Cells in the Hypothalamus Synthesize ADH and Oxytocin and Secrete them in the Posterior Pituitary
Oxytocin and ADH are Chains of 9 Amino Acids
Oxytocin Contracts the Uterus and Myoepithelial Cells of Alveoli Cells in the Breast
Increased Plasma Osmolarity and Decreased Blood Volume Stimulate ADH Release
The Hypothalamus Controls Release of Hormones from the Anterior Pituitary
Multiple Signals Produces Pulsatile Release of GH
The Complicated GH Secretion Pattern Is Produced by Complicated Neuronal Circuits
GH Mediates Some of Its Effects Through Increased IGF-I
Summary
Review Questions
9.3. The Thyroid Gland
The Thyroid Gland Is One of the Largest Endrocrine Glands
The Thyroid Gland Consists of Thousands of Follicles that Store Thyroglobulin
The Thyroid Follicle Secretes Thyroxine and Triiodothyronine
Follicular Cells Secrete Thyroglobulin Precursor into the Follicle
Synthesis of Thyroxine Requires Four Steps
Follicular Cells Proteolyze Thyroglobulin to Release T4 and T3
TSH Regulates State of the Thyroid Gland
The Hypothalamus Partly Controls TSH Release
T4 and T3 Inhibit Secretion of TSH
Almost all Circulating T4 and T3 Are Bound to Plasma Proteins
The Tissues Metabolize T4 to T3 and rT3; T3 is the Active Metabolite
T3 Alters Gene Expression
Thyroid Hormone Plays A Crucial Role in Growth and Development and in General Metabolism
Hypothyroidism Refers to Reduced Circulating Levels of T4 and T3
The Clinical Symptoms of Hypothyroidism Are Manifold
The Most Important Clinical Abnormality of Hyperthyroidism is Graves’ Disease
Summary
Review Questions
9.4. The Endocrine Pancreas and Control of Blood Glucose
The Pancreas Has Both Exocrine and Endocrine Functions
β Cells Synthesize Insulin as a Prohormone and Secrete Insulin and C peptide 1:1
High Plasma Glucose Stimulates Insulin Secretion
Glucagon, GLP-1, and GIP Stimulate Insulin Secretion; Somatostatin Inhibits it
Parasympathetic Stimulation Increases Insulin Secretion; Sympathetic Stimulation Inhibits It
Amino Acids Stimulate Insulin Secretion
Sulfonylureas Close the KATP Channel and Thereby Increase Insulin Secretion
Insulin Release Is Pulsatile
Insulin Phosphorylates Insulin Receptor Substrates via a Tyrosine Kinase
Low Glucose Stimulates Glucagon Release from α Cells in the Islets of Langerhans
Glucagon Stimulates Liver Glycogenolysis through a Gs and Gq Mechanism
Blood Glucose Is Maintained Between 70 and 110 mg% in the Face of Constant Depletion
Plasma Glucose Concentrations Are Maintained by Absorption, Glycogenolysis, and Gluconeogenesis
Multiple Hormones and Nerves Control Glucose Flux
Exercise Has an Insulin-Like Effect
Summary
Review Questions
9.5. The Adrenal Cortex
The Adrenal Glands Lie Atop the Kidneys, Are Richly Vascularized, and Secrete Many Hormones
Steroid Hormones Derive from Cholesterol
The Pituitary–Hypothalamus Axis Controls Adrenal Function through ACTH
ACTH Increases Adrenal Cortical Steroid Secretion
Cortisol Binding Protein Carries Glucocorticoids in Blood
Cortisol Affects Target Cells through Regulation of Transcription
Cortisol Affects Many Body Functions
The Zona Glomerulosa Makes Aldosterone in Response to Angiotensin II, ACTH and K+
Angiotensin II Exerts Multiple Effects
Aldosterone Increases Na+ Reabsorption and K+ Secretion by Genomic and Nongenomic Mechanisms
Summary
Review Questions
9.6. The Adrenal Medulla and Integration of Metabolic Control
The Adrenal Medulla Is Part of the Sympathetic Nervous System
Epinephrine Derives from Tyrosine
Catecholamines Are Released in Response to Sympathetic Stimulation
Catecholamines Are Degraded Rapidly
Actions of Catecholamines Are Mediated by Adrenergic Receptor Types
The Effects of Catecholamines Are to Prepare the Body for “Fight or Flight”
Integration of Metabolic Control
Summary
Review Questions
9.7. Calcium and Phosphorus Homeostasis I
Calcium Homeostasis Is Required for Health
About Half of Plasma Calcium Is Free: The Other Half Is Complexed or Bound to Plasma Proteins
Failure to Regulate Plasma [Ca2+] Causes System Malfunction
Plasma Ca2+ Homeostasis Results from a Balance of Sources and Sinks
Plasma Ca2+ Homeostasis Is Linked to P homeostasis
Plasma Pi Is Present in Multiple Ionized Forms
Plasma [Pi] Is Set by a Balance Between Sources and Sinks
Overall Ca2+ and Pi Homeostasis Is Controlled by Three Hormones Acting on Three Target Tissues
Hypocalcemia Stimulates PTH Secretion
PTH Secretion Is an Example of Derivative Control
PTH Is Destroyed Rapidly After Secretion
PTH Defends Against Hypocalcemia by Actions on Bone and Kidney
CT Is Secreted in Response to Hypercalcemia and Gastrointestinal Hormones
CT Tends to Lower Plasma [Ca2+]
“Vitamin D” Is a Hormone, not a Vitamin, Synthesized in the Skin
Vitamin D Does not Fit Standard Definitions of Either Vitamin or Hormone
The Liver Activates Vitamin D by 25-Hydroxylation: The Kidney Activates It by 1-Hydroxylation
Vitamin D Inactivation Begins with 24-Hydroxylation
PTH Controls Metabolism of Vitamin D
Vitamin D Has Two Forms of Equal Potency in Humans
25(OH)2-D Is the Major Circulating Form of Vitamin D
Vitamin D Maintains Conditions for Bone Mineralization
Summary
Review Questions
9.8. Calcium and Phosphorus Homeostasis II
The Skeleton Gives Us Form and Support
Osteoblasts Are Surface Cells That Lay Down the Organic Matrix of Bone
Osteocytes are Embedded Deep within Bone
Osteoclasts Destroy the Organic Matrix of Bone and Release Both Ca2+ and Pi
Bone Is Constantly Being Remodeled
Osteoblasts Make Osteoid and Signal Bone Resorption
Osteoclasts Resorb Bone
Calcitonin Shuts Off Osteoclast Resorption
Summary of Hormone Effects on Bone
Only 1,25(OH)2-D Directly Affects Intestinal Ca2+ and Pi Absorption
The Intestine Adapts to Diets Containing Differing Amounts of Ca2+ and Pi
Regulation of Urinary Excretion of Ca2+ and Pi Is Achieved in the Distal Nephron
The “Goals” of PTH, CT, and Vitamin D Are Distinct
Integrated Control of Plasma [Ca2+] and Pi Involves Multiple Negative Feedback Loops
Summary
Review Questions
9.9. Female Reproductive Physiology
Sexual Reproduction Costs a Lot but it is Worth the Price
The Anatomy of the Female Reproductive Tract
Overiew of Female Reproductive Function
Oogenesis Begins in the Fetus
Puberty Initiates Ovulation and Development of Secondary Sex Characteristics
LH and FSH Drive the Menstrual Cycle
Overview of Follicular Development
Cellular Aspects of Follicular Development
Ovarian Steroidogenesis Requires Two Cell Types and Two Hormones
Central Hormonal Control of the Menstrual Cycle
LH and FSH Surge Induces Ovulation
After Ovulation, the Follicle Forms the Corpus Luteum
Summary
Review Questions
9.10. Male Reproductive Physiology
Somatic Cells Divide by Mitosis; Germ Cells Divide by Meiosis
Mitosis Produces Two Daughter Cells with the Same DNA Content as the Original Cell
Meiosis Divides the Parent Genome in Half—But Crossing-Over Diversifies the Result
Reassortment of Genetic Material Arises from Two Sources: Independence of Homologous Chromosome Sorting and Crossing-Over
Testicles Produce Sperm and Testosterone
The Hypothalamus and Anterior Pituitary Control Testicular Function
Both LH and FSH Control Testicular Function
The Male Sexual Response
Summary
Review Questions
Problem Set 9.1. Ligand Binding
APPENDIX I. Important Equations
APPENDIX II. Important Physical Constants for Physiology
Glossary
Index
Product details
- No. of pages: 920
- Language: English
- Copyright: © Academic Press 2012
- Published: February 7, 2012
- Imprint: Academic Press
- eBook ISBN: 9780123821645