I. Introduction intro-09.doc
Comparative physiology-- investigate both general principles
of organismal function
and the exceptions to the general rule
Environmental physiology-- investigate
animal's function in and respond to their natural environments, at all stages
of their life cycles
Evolutionary
physiology--investigate the evolution of traits over long period of time, and
within species.
To explore the genetic basis of physiological traits, and the magnitude
and causes of physiological variation
II. Maintaining
life-- necessary life functions
·
Interrelationship
among body organ systems
·
Maintaining
boundaries
·
Movement
·
Responsiveness
·
Digestion
·
Metabolism
·
Excretion
·
Reproduction
·
Growth
III. Survival
needs
·
Ultimate
goal-- maintain life
·
Nutrients
·
Oxygen
·
Water
·
Maintenance of body
temperature
·
Atmospheric pressure
IV. Mechanism and origin: Physiology’s two central questions
·
The study of mechanism
How do modern-day animals carry out their functions?
Why so modern-day animals possess the mechanisms
they have?
V. Natural Selection—key process of
evolutionary origin
Two basic concepts
A.
Fitness-- linked to adaptation
B.
Environment-- microenvironment /kind of habitat in which an animal
lives-- biome
·
Problems
the animal will encounter
·
Kinds
of design and strategy it is likely to show
·
Microenvironment
(microhabitat)-- each individual animal has its own environment
--both biotic and physical— commonly modified by its
own behavioral choices
VI. Environmental components:
A. Environmental stress
·
Abiotic--
physical and chemical
·
Biotic--
direct and indirect effects of other organisms, e.g. competition
B. Magnitude of fluctuations
·
Long
term changes-- land masses move, sea levels rise and fall
·
Short
term changes-- lunar or daily cycle- important in relation to
local microenvironments, and
therefore to small animals
C. Energy or resource
availability-- food chain vs. metabolism
VII. Adaptation
A.
Characters
or traits observed in animals-- result of selection.
For example-- hemoglobin--
better O2 carrier
B.
A
process-- natural selection adjusts the frequency of genes that code for traits
affecting fitness
C.
Short
term compensatory changes: acclimation,
acclimatization
VIII. Responses of animal to changes in
environmental condition
A.
Avoidance--
mechanism for getting away from an environmental problem in space or time.
B.
Conformity--
animals undergo changes of internal state similar to accommodate
changes in the external
environment.
Animals do not attempt to maintain a homeostatic condition for the
whole body
C. Regulation-- animals maintain some or all of the
"normal" internal conditions
D. Behavior
IX. Homeostasis
A. Functions-
Maintenance
of stable internal conditions
B.
Control mechanisms
Communication
Receptor,
control center, effector
Interrelationships
C.
Negative feedback mechanism
1.
Opposite directional change
2.
Decrease in original stimulus
3.
Nervous system controls
4.
Endocrine system controls
5.
Other system controls
D. Positive feedback mechanisms
1.
Same directional change
2.
Increase in original stimulus
3.
Cascade effect
4.
Cardiovascular system controls
5.
Reproductive system controls