1. Introduction to Physiological Principles

2. Our teaching team

3. Grading for the first term
* ATTENDANCE IN ALL LABS IS MANDATORY.
**MIDTERMS: Combinations of multiple choice, short answers, long answers.
Note: ALL midterms, class presentations, research paper and lab requirements must be completed to obtain a passing grade in the course.

4. Research Paper
Use peer-reviewed journal papers (since 2005) as source of your research paper.
3 - 5 word-processed pages (not including references or figures/tables).
Structure : Title page, Abstract/Summary, Main text (depending on the topic you selected, you can have several subheadings in this section), Conclusion, References, Tables, List of figures and figures.
The grading criteria: originality and relevance of the topic; thorough understanding of the cited papers; clarity of presentation; organization of the presentation in an easy to follow/understood format.

5. Physiology “The study of how animals work”
Knut Schmidt-Nielsen (1915–2007)
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

6. 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

7. Biological Level of Organization
Organismal physiology
Systems physiology
Ecological physiology
Cell and molecular physiology
Integrative physiology
Figure 1.2

8. 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

9. Process that Causes Physiological Variation
Developmental physiology
Change as animal grows
Environmental physiology
Change in response to environment
Evolutionary physiology
Change due to natural selection

10. Ultimate Goals of the Research
Pure physiology
No specific goal, other than knowledge
Applied physiology
Medical physiology
Comparative physiology
August Krogh principle – “For every biological system there is an organism on which it can be most conveniently studied”

11. 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

12. Physics and Chemistry
Physical properties of cells and tissue are linked to structure and function (linked to molecular structure)
Molecular interactions are governed by chemical laws
Thermodynamics and kinetics
Electrical laws describe membrane function; especially excitable cells
Membrane potential used to send signals within and between cells (i.e. nerves and muscles)

13. Physics and Chemistry Body size influences physiological patterns
Allometric scaling
Figure 1.3

14. Physiological Regulation
Strategies for coping with changing conditions
Conformers – allow internal conditions to change with external conditions
Regulators – maintain relatively constant internal conditions regardless of external conditions

15. Homeostasis
Maintenance of internal conditions in the face of environmental perturbations
Animals initiate specific responses to control/regulate a particular variable
Some strategies are effective in the short term
Some strategies require significant resources and longer time to take effect
Some stressors are predictable (often cyclic)
Cyrcadian
Sesonal
Lunar cycles

16. Homeostasis Controlled by feedback loops or reflex control pathways
Antagonistic controls – independent regulators with opposite effects
Negative feedback loops
Positive feedback loops
Figure 1.4

17. Phenotype, Genotype, and the Environment
Phenotype is a product of genotype and its interaction with the environment
Genotype – genetic makeup
Phenotype – morphology, physiology, and behavior

18. Factors Influencing Phenotype
Figure 1.1

19. Phenotypic plasticity
Single genotype generates more than one phenotype depending on environmental conditions.
Can be irreversible or reversible
Irreversible
Polyphenism – developmental plasticity
Reversible
Acclimation – under laboratory conditions
Acclimatization – natural environment
Figure 1.5

20. Phenotypic Plasticity - Polyphenism

21. Physiology and Evolution
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?

22. Adaptation Two distinct meanings
Change in a population over evolutionary time (i.e., many generations)
Most common usage
Definition used in this book
Synonym for acclimation
Many argue this is an incorrect usage

23. 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

24. 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

25. 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

26. Unifying Themes in Physiology
Table 1.1