1. Central Themes of Animal Physiology
I. Structure-Function
II. Change
III. Homeostasis
IV. Conformity and Regulation

2. I. Factors That Influence Structure-Function
A. Mechanical
B. Electrical
C. Thermal
D. Body Size

3. Phenotypic plasticity

4. II. Change Adaptation (evolutionary) via natural selection
promotes  survivability and reproduction
via DNA
propagation is the ultimate physical drive (survival)
Acclimatization
change in an individual
response to a new or altered environment
Acclimation
similar to acclimatization
changes are induced experimentally

5. III. Homeostasis
The process by which an organism maintains the “constancy” of its internal environment.
Disease = change in internal environment which exceeds normal parameters.
Receptors (sensors)
 Integrating center
 Effector
Set point
Feedback: the coupling of the output of a process to the input.

6. III. Homeostasis
Negative feedback: An action directly opposes (corrects) the variation.
Positive feedback: Initial stimulus produces a response that further increases the magnitude of the stimulus.
Antagonistic effectors: Increase in one effector’s activity is coupled with a decrease in another’s.

7. IV. Conformity and Regulation
Conformers
cannot control internal conditions in response to outside changes
osmoconformers: internal fluids conform to external fluids
sea stars
oxyconformers: O2 consumption changes with external levels
annelid worms

8. Regulators
maintain internal conditions in response to external changes
osmoregulators: maintain [ions] internally regardless of external fluids
oxyregulators: steady consumption of O2 regardless of external changes
crayfish, most mollusks, most vertebrates
most “inverts” are conformers and most “verts” are regulators

9. IV. Conformity and Regulation
Regulation is expensive, but has its advantages.
Some animals are both conforming and regulating depending on the parameter.

11. Iguana body temperature