Principles of Animal physiology
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
偉明圖書
02-23638586
02-23636567
CHAPTER
1
Introduction to
Physiological
Principles
PowerPoint® Lecture Slides prepared by
Stephen Gehnrich, Salisbury University
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Physiology
“The study of how animals work” (1915–)
Structure and function of various parts
 How these parts work together
Diversity of animals
 More than 1 million species live on Earth
Unifying themes
 Apply to all physiological processes
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Factors influencing the phenotype of animals
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Physiological Subdisciplines
Based on




Biological level of organization
Process that causes physiological variation
Ultimate goals of the research
Many physiological questions encompass elements
from each subdiscipline
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Biological Level of Organization
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Figure 1.2
Biological Level of Organization
 Cell and molecular physiology
 Genetics, metabolism, signal transduction, organelles
 Systems physiology
 Function of organs, interaction, Part II
 Organismal physiology
 Whole animal (avian..), metabolic rate to stress
 Ecological physiology
 Animal and its environment, nutrient
 Integrative physiology
 Multiple levels of organization, hemoglobin gene
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Biological Level of Organization
Physiologists often study processes at more than one
level
 Reductionism – understand a system by studying
the function of its parts
 Emergence – the whole is more than the sum of its
parts
 Molecules, cells and tissue interaction
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Process that Causes Physiological Variation
 Developmental physiology
 Change as animal grows, stem cells
 Environmental physiology
 Change in response to environment, temperature
 Evolutionary physiology
 Change due to natural selection
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Ultimate Goals of the Research
 Pure physiology
 No specific goal, other than knowledge
 Applied physiology
 Medical physiology
 Veterinary medicine
 Comparative physiology
 August Krogh principle – “For every biological
system there is an organism on which it can be most
conveniently studied”
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Animal model
BALB/c
Nude
SCID
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Unifying Themes in Physiology
 Physiological processes obey physical and
chemical laws
 Physiological processes are usually regulated
 Homeostasis – maintenance of internal constancy
 Physiological phenotype is a product of genotype
and environment
 Genotype – genetic makeup
 Phenotype – morphology, physiology, and behavior
 Genotype is the product of evolution
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Unifying Themes in Physiology
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Table 1.1
Physics and Chemistry
 Physical properties of cells and tissue are linked to
structure and function-protein, lipidmacromolecules-bone
 Molecular interactions are governed by chemical
laws
 Thermodynamics and kinetics
 Electrical laws describe membrane function;
especially excitable cells
 Nerves and muscles
 Body size influences physiological patterns
 Allometric scaling
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Physics and Chemistry
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Figure 1.3
Physiological Regulation
Strategies for coping with changing conditions
 Conformers – allow internal conditions to change
with external conditions-fish
 Regulators – maintain relatively constant internal
conditions regardless of external conditions-37℃
 Conformers + Regulators
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Homeostasis
Maintenance of internal conditions in the face of
environmental perturbations
Controlled by feedback loops or reflex control
pathways
 Negative feedback loops-eat, set-point
 Positive feedback loops-toxin and vomiting
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Homeostasis
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Figure 1.4
Phenotype, Genotype, and the Environment
Phenotype is a product of genotype and its
interaction with the environment
 Genotype – genetic makeup-frog, muscle exercise
 Phenotype – morphology, physiology, and behavior
 Phenotypic plasticity – single genotype generates
more than one phenotype depending on
environmental conditions -twins
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Factors Influencing Phenotype
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Figure 1.1
Phenotype, Genotype, and the Environment
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Figure 1.5
Phenotypic Plasticity
Can be irreversible or reversible
 Irreversible
 Polyphenism – developmental plasticity
 Reversible
 Acclimation – under laboratory conditions
 Acclimatization – natural environment
 Fish-15℃ or 5℃
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Physiology and Evolution (1)
Diversity of anatomic and physiologic strategies
animals use to cope with their environment
Two types of questions
 Proximate cause
 How did these develop?
 Ultimate cause
 Why are these changes helpful?
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Physiology and Evolution (2)
 Proximate cause
 Ultimate cause
 Respiratory, cardiovascular, evolutionary
Okapi
Giraffe
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Adaptation
Two distinct meanings
 Change in a population over evolutionary time
(i.e., many generations) –muscle and heart
 Most common usage
 Synonym for acclimation
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Basis for Evolution and Natural Selection
 Variation among individuals for specific traits
 Traits must be heritable
 Traits must increase fitness
 That is, must increase reproductive success
 Relative fitness of different genotypes depends on
the environment
 If the environment changes, the trait may no longer be
beneficial
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Not All Differences are Adaptations
Genetic drift
 Random changes in the frequency of genotypes
over time
 Independent of adaptive evolution
 Most common in small populations
 For example, forest fire resulting in founder effect
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Evolutionary Relationships
 Despite the diversity in animal form and function,
there are many similarities
 Common evolutionary ancestors
 Closely related species share more features than
distantly related species
 Understanding evolution is necessary to
understanding physiological diversity
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings