BIO 203: Principles of Physiology and Thermoregulation

Physiology

Study of functions in living organisms.

ATP

Energy currency of the cell.

ADP

Adenosine diphosphate, lower energy than ATP.

Na+

Sodium ion, important for cellular function.

K+

Potassium ion, crucial for nerve impulses.

Homeostasis

Maintenance of stable internal conditions.

Thermoregulation

Process of maintaining body temperature.

Heat Transfer

Movement of thermal energy between systems.

Positive Feedback

Enhances change in a system.

Negative Feedback

Reduces change to maintain stability.

Aerobic Metabolism

Energy production using oxygen.

Anaerobic Metabolism

Energy production without oxygen.

Vital Substances

Essential materials for life processes.

Exchange Systems

Systems facilitating material transfer in organisms.

Respiratory System

Exchanges oxygen and carbon dioxide.

Digestive System

Processes nutrients and water absorption.

Urinary System

Removes waste and regulates water.

Circulatory System

Distributes blood and nutrients throughout body.

Cellular Level

Basic unit of structure and function.

Tissue Level

Groups of similar cells performing functions.

Organ Level

Different tissues working together for specific tasks.

System Level

Multiple organs cooperating for major functions.

Aquatic Life

All life forms primarily exist in water.

Compartmentalization

Separation of substances into distinct cellular compartments.

Fundamental Problems

Common challenges faced by all living organisms.

Laws of Physics

Natural laws governing biological processes and structures.

Limited Conditions

Organisms can only survive within specific environmental ranges.

Body Fluids Composition

Body fluids resemble seawater in chemical makeup.

Water Percentage in Humans

Water constitutes 75% of human body weight.

Molecular Composition

99% of human molecules are water.

Salts in Body

0.75% of body molecules are inorganic salts.

Biochemical Substances

0.25% of molecules include proteins and nucleic acids.

Intracellular Fluid (ICF)

Fluid found inside cells.

Extracellular Fluid (ECF)

Fluid located outside of cells.

Interstitial Fluid

ECF not contained in the circulatory system.

Plasma

Liquid component of blood.

Asymmetric Ion Distribution

Different ion concentrations in ICF and ECF compartments.

Sodium Levels in ECF

Sodium concentration is high in extracellular fluid.

Potassium Levels in ICF

Potassium concentration is high in intracellular fluid.

Physiological Asymmetry

Essential for maintaining cellular functions.

Adenosine Triphosphate (ATP)

Main energy currency used in cellular processes.

Metabolic Rate (MR)

Energy expenditure measured over time.

Surface Area to Volume Ratio

Index for exchange efficiency in organisms.

Size Principle

Relationship between animal size and heat exchange.

Large Animal Heat Exchange

Low heat exchange per unit volume.

Small Animal Heat Exchange

High heat exchange per unit volume.

Heat Retention

Ability to maintain temperature within body.

Good Heat Retention

Characteristic of large animals.

Poor Heat Retention

Characteristic of small animals.

Cell-to-Cell Communication

Necessary for maintaining homeostasis.

Feedback System Components

Sensor, integrator, and effector are essential.

Sensor

Measures aspect of internal environment (e.g., temperature).

Integrator

Compares sensor measurement to reference value.

Effector

Changes internal environment based on sensor input.

Set Point

Desired value for a physiological parameter.

Thermostat Example

Illustrates negative feedback in temperature regulation.

Physiological Ecology

Study of organism's relationship to environment.

Heat Definition

Kinetic energy from molecular motion.

Temperature Definition

Measure of heat intensity in an object.

Water and Ion Balance

Context for physiological ecology and homeostasis.

Body Temperature Regulation

Mechanisms to maintain optimal body temperature.

Temperature

Index of molecular motion and kinetic energy.

Thermal Budget

Balance of heat gained and lost.

Conduction

Heat transfer through physical contact.

Convection

Heat transfer via moving fluids or gases.

Evaporation

Liquid water transforms to vapor, cooling body.

Radiation

Heat transfer through electromagnetic waves.

Heat Gain

Heat obtained from external environment.

Heat Loss

Heat lost to external environment.

Endogenous Heat Production

Heat generated internally via metabolism.

Temperature Gradient

Difference in temperature driving heat flow.

Thermal Conductivity (K)

Material's ability to conduct heat (W x m-1 x K-1).

Surface Area (A)

Area of contact influencing heat transfer rate.

Length (l)

Distance between objects affecting heat movement.

Differential Equations

Mathematical equations describing heat transfer rates.

Free Convection

Natural movement of fluid due to temperature differences.

Forced Convection

Fluid movement induced by external forces.

Boundary Layers

Thin layers affecting heat exchange efficiency.

Evaporative Cooling

Cooling effect from water vaporization.

Heat of Vaporization

Energy required to convert liquid to vapor.

Infrared Electromagnetic Radiation

Longer wavelengths with lower energy.

Vasodilation

Widening of blood vessels to increase heat loss.

Vasoconstriction

Narrowing of blood vessels to reduce heat loss.

Core Body Temperature

Average temperature for physiological function.

Counter-Current Exchange Mechanism

Heat transfer between arterial and venous blood.

Ectothermy

Thermoregulation using external heat sources.

Endothermy

Thermoregulation using internal metabolic heat.

Heterothermy

Combination of internal and external heat regulation.

Ambient Temperature (Tamb)

Temperature of the surrounding environment.

Poikilotherms

Organisms with variable body temperature.

Homeotherms

Organisms maintaining constant body temperature.

Thermoregulation Strategies

Methods organisms use to control body temperature.

Physiological Thermoregulation

Internal mechanisms for temperature control.

Behavioral Thermoregulation

Actions taken to regulate body temperature.

Thermal Acclimation

Physiological adjustments to temperature changes.

Hibernation

Extended state of inactivity during cold periods.

Torpor

Short-term hibernation-like state for energy conservation.

Estivation

Dormancy during hot, dry periods.

Fever Generation

Increased body temperature response to infection.

Hypothalamus Role

Regulates body temperature and fever response.