Environmental Biology and Physiology

4.

The Gaseous Environment

4.1.

Properties of Gases in Air and Water

4.1.1.

Partial Pressure

4.1.1.1.

4.1.1.2.

Atmospheric Composition

4.1.1.3.

Altitude Effects

4.1.1.4.

Pressure Calculations

4.1.2.

4.1.2.1.

4.1.2.2.

Temperature Effects

4.1.2.3.

Salinity Effects

4.1.2.4.

Gas-specific Differences

4.1.3.

Diffusion Gradients

4.1.3.1.

4.1.3.2.

Concentration Differences

4.1.3.3.

Distance Effects

4.1.3.4.

Surface Area Importance

4.1.4.

Temperature and Salinity Effects

4.1.4.1.

Solubility Changes

4.1.4.2.

Diffusion Rate Changes

4.1.4.3.

Biological Implications

4.2.

Respiratory Structures and Gas Exchange

4.2.1.

Cutaneous Respiration

4.2.1.1.

Limitations and Adaptations

4.2.1.1.1.

Surface Area Constraints

4.2.1.1.2.

Permeability Requirements

4.2.1.1.3.

Circulatory Support

4.2.1.1.4.

Environmental Dependencies

4.2.2.

4.2.2.1.

Structure and Function

4.2.2.1.1.

Filament Organization

4.2.2.1.2.

Lamellae Arrangement

4.2.2.1.3.

Blood Flow Patterns

4.2.2.1.4.

Ventilation Mechanisms

4.2.2.2.

Countercurrent Exchange Mechanism

4.2.2.2.1.

Blood and Water Flow

4.2.2.2.2.

Efficiency Advantages

4.2.2.2.3.

Oxygen Extraction

4.2.2.2.4.

Carbon Dioxide Elimination

4.2.3.

Tracheal Systems

4.2.3.1.

Insect Respiration

4.2.3.1.1.

Spiracle Function

4.2.3.1.2.

Tracheal Branching

4.2.3.1.3.

Direct Oxygen Delivery

4.2.3.1.4.

Ventilation Mechanisms

4.2.3.2.

Spiracle Regulation

4.2.3.2.1.

Opening and Closing

4.2.3.2.2.

Water Loss Control

4.2.3.2.3.

Carbon Dioxide Regulation

4.2.4.

4.2.4.1.

Vertebrate Lung Diversity

4.2.4.1.1.

Amphibian Lungs

4.2.4.1.2.

Reptilian Lungs

4.2.4.1.3.

Mammalian Lungs

4.2.4.1.4.

4.2.4.2.

Alveolar and Parabronchial Lungs

4.2.4.2.1.

Structural Differences

4.2.4.2.2.

Gas Exchange Efficiency

4.2.4.2.3.

Ventilation Patterns

4.2.4.2.4.

Evolutionary Adaptations

4.3.

Transport of Oxygen and Carbon Dioxide in Body Fluids

4.3.1.

Respiratory Pigments

4.3.1.1.

4.3.1.1.1.

Structure and Oxygen Binding

4.3.1.1.1.1.

4.3.1.1.1.2.

Protein Structure

4.3.1.1.1.3.

Cooperative Binding

4.3.1.1.1.4.

Allosteric Effects

4.3.1.2.

4.3.1.2.1.

Copper-based Oxygen Binding

4.3.1.2.2.

Molluscan and Arthropod Systems

4.3.1.2.3.

Temperature Sensitivity

4.3.1.3.

4.3.1.3.1.

Iron-based Oxygen Binding

4.3.1.3.2.

Marine Invertebrate Systems

4.3.1.3.3.

Oxygen Affinity

4.3.1.4.

4.3.1.4.1.

Iron-based Green Pigment

4.3.1.4.2.

Polychaete Worms

4.3.1.4.3.

Oxygen Transport

4.3.2.

Oxygen Equilibrium Curves

4.3.2.1.

Oxygen Dissociation Curves

4.3.2.1.1.

Sigmoidal Shape

4.3.2.1.2.

4.3.2.1.3.

Hill Coefficients

4.3.2.1.4.

Species Variations

4.3.2.2.

Factors Affecting Affinity

4.3.2.2.1.

Temperature Effects

4.3.2.2.2.

4.3.2.2.3.

Carbon Dioxide Effects

4.3.2.2.4.

Organic Phosphate Effects

4.3.3.

The Bohr Effect

4.3.3.1.

pH-dependent Oxygen Binding

4.3.3.2.

Physiological Significance

4.3.3.3.

Tissue Oxygen Delivery

4.3.3.4.

Species Variations

4.3.4.

The Root Effect

4.3.4.1.

pH-induced Oxygen Release

4.3.4.2.

Swim Bladder Function

4.3.4.3.

Retinal Oxygen Supply

4.3.4.4.

Fish-specific Adaptations

4.3.5.

Carbon Dioxide Transport

4.3.5.1.

4.3.5.1.1.

Physical Solubility

4.3.5.1.2.

Concentration Gradients

4.3.5.1.3.

Transport Limitations

4.3.5.2.

Bicarbonate Formation

4.3.5.2.1.

Carbonic Anhydrase

4.3.5.2.2.

4.3.5.2.3.

4.3.5.3.

Buffering Systems

4.3.5.3.1.

Hemoglobin Buffering

4.3.5.3.2.

4.3.5.3.3.

4.4.

Responding to Hypoxia and Anoxia

4.4.1.

Aquatic Hypoxia

4.4.1.1.

Behavioral and Physiological Responses

4.4.1.1.1.

Surface Breathing

4.4.1.1.2.

Gill Ventilation Changes

4.4.1.1.3.

Metabolic Adjustments

4.4.1.1.4.

4.4.2.

Burrowing and Fossorial Life

4.4.2.1.

Adaptations to Low Oxygen

4.4.2.1.1.

Enhanced Oxygen Extraction

4.4.2.1.2.

Reduced Metabolic Demands

4.4.2.1.3.

Behavioral Modifications

4.4.2.1.4.

Morphological Adaptations

4.4.3.

Metabolic Depression

4.4.3.1.

Anaerobic Metabolism

4.4.3.1.1.

Glycolytic Pathways

4.4.3.1.2.

Fermentation Products

4.4.3.1.3.

4.4.3.1.4.

4.4.3.2.

Lactate Accumulation and Clearance

4.4.3.2.1.

Production Rates

4.4.3.2.2.

Tissue Tolerance

4.4.3.2.3.

Recovery Mechanisms

4.4.3.2.4.

Buffering Capacity

4.5.

High-Altitude Physiology

4.5.1.

Hypobaric Hypoxia

4.5.1.1.

Environmental Challenges

4.5.1.1.1.

Reduced Oxygen Partial Pressure

4.5.1.1.2.

Temperature Effects

4.5.1.1.3.

4.5.1.1.4.

Dehydration Risks

4.5.2.

Ventilatory Acclimatization

4.5.2.1.

Hyperventilation

4.5.2.1.1.

Increased Breathing Rate

4.5.2.1.2.

Increased Tidal Volume

4.5.2.1.3.

Respiratory Alkalosis

4.5.2.1.4.

Renal Compensation

4.5.2.2.

Chemoreceptor Sensitivity

4.5.2.2.1.

Carotid Body Responses

4.5.2.2.2.

Central Chemoreceptors

4.5.2.2.3.

Adaptation Changes

4.5.3.

Hematological Responses

4.5.3.1.

Erythropoietin Production

4.5.3.1.1.

Kidney EPO Synthesis

4.5.3.1.2.

Hypoxia-inducible Factors

4.5.3.1.3.

4.5.3.2.

Hemoglobin Concentration

4.5.3.2.1.

Red Blood Cell Production

4.5.3.2.2.

Hematocrit Changes

4.5.3.2.3.

Oxygen Carrying Capacity

4.5.4.

Cardiovascular Adjustments

4.5.4.1.

4.5.4.1.1.

Heart Rate Changes

4.5.4.1.2.

Stroke Volume Changes

4.5.4.1.3.

Pulmonary Circulation

4.5.4.2.

Capillary Density

4.5.4.2.1.

4.5.4.2.2.

Tissue Oxygen Delivery

4.5.4.2.3.

Diffusion Distances

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3. Water and Solute Balance

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5. Other Abiotic Environmental Factors