Transcript Ch. 40 Basic Principles of Animal Form and Function note

LO 2.9 The student is able to represent graphically or model quantitatively the exchange of molecules between an
organism and its environment, and the subsequent use of these molecules to build new molecules that facilitate
dynamic homeostasis, growth and reproduction.
LO 2.12 The student is able to use representations and models to analyze situations or solve problems qualitatively and
quantitatively to investigate whether dynamic homeostasis is maintained by the active movement of molecules across
membranes.
LO 2.21 The student is able to justify the selection of the kind of data needed to answer scientific questions about the
relevant mechanism that organisms use to respond to changes in their external environment.
LO 2.25 The student can construct explanations based on scientific evidence that homeostatic mechanisms reflect
continuity due to common ancestry and/or divergence due to adaptation in different environments.
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LO 2.26 The student is able to analyze data to identify phylogenetic patterns or relationships, showing that homeostatic
mechanisms reflect both continuity due to common ancestry and change due to evolution in different environments.
LO 2.27 The student is able to connect differences in the environment with the evolution of homeostatic mechanisms.
LO 2.28 The student is able to use representations or models to analyze quantitatively and qualitatively the effects of
disruptions to dynamic homeostasis in biological systems.
LO 2.34 The student is able to describe the role of programmed cell death in development and differentiation, the reuse
of molecules, and the maintenance of dynamic homeostasis.
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We are starting the anatomy and physiology unit:
o Anatomy – biological form (structure of organisms)
o Physiology – biological function (how the structures work)
o EX: a jackrabbit has large ears (anatomy) to help regulate
temperature (physiology)
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Evolution of Animal Size and Shape
o Convergent evolution – fast swimmers have similar anatomies.
o Arms race – how big can your body get before it collapses of its own
weight? How will you get the energy all of your cells need if you have
a lot more of them? (Irish Elk – horns got so big it couldn’t move
anymore and went extinct!)
Seal
Tuna
Penguin
Either every cell of an organisms needs to be in direct contact with the
outside world (amoeba & hydra) or it requires a way to transport
materials to its cells. Interstitial fluid surrounds cells for and holds
materials outside of it.
o Branching or folding of tissues increases the surface area:volume, thus
External environment
CO2 O
Food
2
Mouth
Animal
body
Respiratory
system
Lung tissue (SEM)
Heart
Digestive
system
Nutrients
Lining of small
intestine (SEM)
Cells
Interstitial
fluid
Circulatory
system
Anus
Metabolic waste products
(nitrogenous waste)
50 m
Excretory
system
Unabsorbed
matter (feces)
250 m
increasing the ability for exchange.
100 m
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Blood vessels in
kidney (SEM)
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Cells 
Tissues (epithelial, connective, muscle, & nervous)
Organs 
Organ Systems (digestive, circulatory,
respiratory, immune/lymphatic,
excretory, endocrine, reproductive,
nervous, integumentary, skeletal, &
muscular)
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Endocrine System:
o Hormones travel through the
bloodstream throughout the whole
body but only effect cells with the
appropriate receptor for it.
o Slow acting and long-lasting
effects, such as
growth/development,
reproduction, and metabolism.
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Nervous System:
o Impulse between specific target
cells (neurons, muscle, endocrine,
and exocrine cells).
o Very fast.
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Regulators maintain a constant internal environment despite
changes in its surroundings.
Conformers’ internal environment changes with the surroundings.
o Some organisms do both (Ex: bass regulate solute concentrations but
conform to temperature).
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“Steady State;” maintaining a constant internal
environment.
Mechanism (like room temp.) for a variable:
o Set point (or range): the needed value to maintain
o Stimulus: fluctuates the above/below set point
o Response: a sensor sends a signal to the control center (brain)
triggering a physiological activity that helps return it to the set
point.
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Negative Feedback – reduces/dampens the stimulus
Positive Feedback – amplifies stimulus
Animation: Negative Feedback
Right-click slide / select “Play”
© 2011 Pearson Education, Inc.
Animation: Positive Feedback
Right-click slide / select “Play”
© 2011 Pearson Education, Inc.
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Set points change according to
things such as time and age.
Circadian rhythms cause
physiological changes ever
~24hrs.
o Disruptions in these can be
conformed to but it take time,
called acclimatization. (Ex: jet lag).
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Thermoreguation
o Endotherms are warmed by their metabolism (“warm-blooded”)
o Ectotherms are warmed by their environment (“cold-blooded”)
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Balancing Heat Loss and Gain
o Radiation: emission of electromagnetic waves by all objects warmer
than absolute 0.
o Evaporation: removal of heat from the
surface of a liquid that is losing some of its
molecules as gas.
o Convection: transfer of heat by the
movement of air or liquid past a surface.
o Conduction: is the direct transfer of thermal
motion (heat) between molecules of objects
in contact with each other.
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Insulation: fur, feathers, and blubber
Circulatory Adaptations
o Blood flows to skin increasing loss of heat
o Restricting blood flow to skin keeps blood from getting too hot on hot days.
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Countercurrent exchange
o Warm-blood (arteries) are close to cooler blood (veins) which flow in opposite
directions (countercurrent)
o Some heat transfers from arterial blood to venous blood.