Term
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Definition
| The total E released in the breakdown of a fuel to a given set of end products is always the same, regardless of intermediate chemical steps or pathways used. |
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Term
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Definition
How fast energy flows through an organism
mlO2/mg |
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Term
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Definition
| Measuring Heat given off by organism (more complex) |
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Term
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Definition
| Mesauring rates of gas consumption, need to know what fuel was (carbs, lipids, proteins) |
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Term
| Respiratory Exchange Ratio (indirect) |
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Definition
| Moles of CO2 produced of time/ moles of O2 consumed at the respiratory organs. Tells you which foodstuffs are being oxidized |
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Term
| Respiratory Quotient (indirect) |
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Definition
| Moles of CO2 produced / moles of Oxygen Used at the cellular levels. Tells you which foodstuffs are being oxidized |
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Term
| Respiratory Gas Exchange (RQ) |
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Definition
| Chemical energy content of food that enters and leaves an animals body (ingestion/egestion) |
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Term
| Material Balance (indirect) |
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Definition
| What materials go into an organism and what materials go out of an organism in a given period of time |
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Term
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Definition
| Increase in metabolic rate caused by food ingestion. Magnitude is based on the total excess metabolic heat production |
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Term
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Definition
| Minimal metabolic rate in the thermoneutral zone that has been resting and fasting (post-absorbative - no more specific dynamic action) |
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Term
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Definition
| Range of temperatures at which the Metabolic rate is constant and minimum |
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Term
| Standard Metabolic Rate (poikilotherms!) |
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Definition
| Metabolic rate of a poikilotherm while it is fasting and resting. |
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Term
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Definition
| Standard Metabolic Rate (SMR). Body temperature varies with environment. Q10 |
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Term
| Metabolic Rate and Body Size |
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Definition
Not proportional, is allometric. IE if you are ten times bigger, you will have a higher metabolic rate, but not 10 times higher. Scaling coefficient is less then one (about .67-.75). Larger animals consume oxygen at a lower rate then smaller animals relative to their body weight.
large organisms have more connective tissue (skeletons are living but not metabolically active)
Diffusion constraints for larger animals |
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Term
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Definition
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Term
| Tyranny of Arrhenius (poikilotherms) |
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Definition
If its cold out, poikilotherms must be inactive. How can they get around this problem?
Acute: Not much that can be done
Chronic:Acclimating |
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Term
| Acclimating vs Acclimization (poikilotherms) |
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Definition
Acclimating is Adaptive Adjustment in physiological or biochemical state or function in response to changes in 1 or 2 well defined factors. Acclimating only occurs in the lab!
Acclimitization- a physiological or biochemical state or function that changes in response to many factors |
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Term
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Definition
Metabolic rate at one temperature divided by the metabolic rate at 10 degrees cooler.
Usually about 2 or 3 (doubling or tripling)
Indicator of temperature sensitivity to metabolic rate |
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Term
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Definition
| Can only survive in a narrow temperature range |
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Term
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Definition
| Can survive in a wide range of temperatures |
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Term
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Definition
| Common variables are ambient temperature - body temperature, surface area, |
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Term
| Conduction (heat transfer) |
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Definition
Diffusive transfer of heat (Tb- Ta)/d
d = distance heat has to travel
the more distance between the two surfaces, the less conduction
air is poor at conduction(it insulates), metal is good at conduction (conductor) |
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Term
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Definition
| Lower Critical Temperature- below this temperature, metabolic rate rises to compensate for heat loss. Insulation is highest at this point |
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Term
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Definition
| Upper Critical Temperature- above this temperature, metabolic rate rises as you actively pursue heat loss through methods outlined in other cards. Conductance is highest at this point |
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Term
| Convection (heat transfer) |
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Definition
Transfer of heat do to the bulk movement of fluids. Faster then conduction.
H = Hc (Ts- Ta)
Hc= convection coefficient.
Enhances conduction. Movement of air keeps ambient temperature at maximum. |
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Term
| Evaporation (heat transfer) |
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Definition
transfer of heat due to conversion of water to gas or vapor phase. Highly effective at heat loss. Sweat and panting are two dominant forms of this.
Surface area, skin permeability to water, humidity (Florida: thats why you are always sweaty) |
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Term
| Radiation (heat transfer) |
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Definition
Everything above 0 degrees K emits radiation.
Surface area, emittance, and Ts^4 (surface temperature to the fourth power) are the factors.
We lose the most heat through radiation. |
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Term
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Definition
Metabolic Rate is minimum and constant at Ta.
Heat gain equals heat loss |
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Term
| Benefits to Poikilothermy |
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Definition
Cheaper Energetically
Dont have to eat as often
Higher assimilation of body mass from their food
poikilothermy diversity is lower in extreme temperature environments |
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Term
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Definition
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Term
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Definition
| estimated limit of enzymatic activity. Lower Vmax means less substrate can be processed vs higher Vmax. Temperature change of 33 degrees celsius to 16 degrees celsius pushes the Vmax down, so must increase Vmax to cope with the temperature change. |
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Term
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Definition
| Substrate concentration where enzyme activity is one half of Vmax. |
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Term
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Definition
| Alternate form of an enzyme in an organism that is formed through gene duplication. Gives organisms a tolerance zone which lowers the lower critical temperature zone. |
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Term
| Reverse Compensation (poikilotherm) |
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Definition
| decrease enzyme concentrations (push down Vmax) so that you can cool down and lower metabolic rate |
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Term
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Definition
| Birds (read: Pelican) use this to help evaporative cooling by using their mouths to cool themselves down. Doesnt induce alkalosis because it only involves oral airflow and no CO2/O2 is exchanged. Can occur with panting |
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Term
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Definition
| Too much panting causes excessive removal of CO2 from the body which increases the pH of the blood and causes passing out. |
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Term
|
Definition
Made of Phospholipids, held together by hydrophobic effect.
When it cools, will solidify and decrease fluidity.
When it warms, increases fluidity.
Poikilotherms decrease activity partly because their membranes are solifigying.
Fatty Acid chain length: shorter results in more fluid, while longer results in less fluid.
Freezing results in osmotic shock, causes risk of dehydration |
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Term
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Definition
| Generate heat metabolically |
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Term
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Definition
| Get heat from environment |
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Term
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Definition
Adjust thermal conductance by increasing thickness of hair or fur.
Birds do this with their feathers. |
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Term
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Definition
| Chemical composition of cell membranes is not fixed, will adjust to changes in ambient temperature |
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Term
| Pros of Preventing Freezing |
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Definition
| Cuts down risk of osmotic shock due to increases in salt concentration (only pure water freezes) |
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Term
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Definition
| Remaining unfrozen even when ones temperature falls below their freezing point. Unstable, and can spontaneously freeze at any moment. Exposure to ice induces freezing. (No ice crystals can be present). Lowers Freezing Point, but melting point is still the same. Must remove nucleating agents to prevent crystallization. |
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Term
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Definition
Colligative antifreezes - increase the total concentration of solutes in body fluids to lower the freezing points of body fluids
Non-colligative - Lowers the freezing point by binding to ice crystals to suppress the growth of ice. Prevents ice crystals from forming. Better than colligative.
Mostly synthesized by fish |
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Term
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Definition
| Solutions whose freezing points are much lower than melting points |
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Term
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Definition
Limit degree of supercooling in extracellular freezing, so this fluid will freeze (expose body to ice crystals). Up to 65% of body water can freeze.
Can tolerate because organic solutes (glycerol, glucose) go into extracellular and intercellular fluids, prevents cell shrinkage, too much extracellular freezing
Protects proteins from denaturing
Freeze ACROSS bodies at SAME time (not outside in), thaw everywhere at once (make sure all tissues get oxygen)
Cell metabolism continues at a very low rate |
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Term
| freezing intolerance methods |
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Definition
behavioral avoidance, antifreeze production, or supercooling
-Antifreeze: lower freezing point
-Supercooling: remain unfrozen while at T below freezing points |
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Term
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Definition
| The range of temperatures in which a poikilotherm can operate normally; can resist temperature sensitivity (keep metabolic rate minimum) |
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Term
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Definition
Most vertebrates can only tolerate temperatures up to about 45-50 (for poikilotherms)
*proteins denature at too high of temperatures |
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Term
| Response to high temperatures |
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Definition
Heat shock proteins induced (HSPs), a type of protein classified by its molecular weight (HSP70, HSP90)
Flow rapidly into the cells to make sure that proteins do no lose their tertiary structure (chaperonins) |
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Term
| Heat Shock Proteins (HSP) |
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Definition
Proteins like chaperonins that help proteins fold into tertiary structure
Can be induced by many stressors: heat, change in salinity, pollutants |
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Term
| Poikilotherms: adjustments for heat |
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Definition
Biochemical changes: can take days or weeks
Physiological/behavioral changes: less powerful but instantaneous effects
REGULATING body temperature, by changing behavior so that heat loss/gain are different based on air/wind/temp/sun |
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Term
| Behavioral adjustments for poikilotherms (response to heat) |
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Definition
body orientation in sun (bask vs. move out of sun) --ECTOTHERMY, can lead to a body T higher than ambient T
*lay on hot rocks, hide in shade (thermal microhabitats)
*body color (if they can change)
*stand in wind for more convective heat loss |
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Term
| Physiological response to heat |
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Definition
Redistribution of blood flow:
*shunt blood to surface: dissipates heat quickly (small distance for the heat to travel from the blood to the skin)
*shunt blood to deeper blood vessels: retard heat flow, slow heart rate |
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Term
| Poikilotherms: endothermic heat production |
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Definition
Some poikilotherms (python, some fish) can use endothermic processes to produce body heat
Pythons: muscle contractions generate metabolic heat to help temperature sensitive eggs develop
Fish: because water is highly conductive of heat (heat loss happens quickly), no insulation
*muscle function more efficient when muscles are warm, so save energy by warming the tissue --> generate heat by moving a lot, and keep the heat where it is generated/needed (muscles) |
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Term
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Definition
Dense network of arteries/veins that allows for countercurrent heat exchange
*warm blood in veins travels next to cool blood in arteries, so the arterial blood is warmed (T gradient)
*allows for heat to stay in the area that has the rete mirable (muscles usually, body core) |
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Term
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Definition
Can thermoregulate: keep a high body temp
about 90% of food is used for generating heat |
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Term
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Definition
C= 1/insulation
C- all factors that affect heat transfer, measure of how much heat an animal will lose
*high C= lose heat quickly, little insulation (max C is at UCT)
*low C= lose heat slowly, have a lot of insulation (min C is at LCT)
*lower min C=shallow slope --> MR will increase slowly below LCT |
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Term
| Homeotherms: heat responses |
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Definition
Behavioral: surface area (reduce by curling up: keep in heat)/posture
Direct blood flow to/away from skin
Adjust thermal conductance |
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Term
| Homeotherms: body size, UCT/LCT |
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Definition
| larger animals have a low C, small SA to mass ratio means that they will have a LOWER UCT and LCT than smaller animals |
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Term
| Homeotherms in different environments |
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Definition
*tropical animals: high LCT because adapt to lose heat efficiently, can't live in cold
*temperate animals: (arctic fox) VERY low LCT, can survive in very cold T, but can easily overheat
*small organisms in cold: high LCT, steep slope above (MR goes up rapidly above LCT)--EXPENSIVE to be small |
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Term
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Definition
Production of heat metabolically
*shivering thermogenesis
*non-shivering thermogenesis |
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Term
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Definition
| Generate heat metabolically through low amplitude, oscillatory muscle contractions |
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Term
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Definition
Body T falls, enzymes can't work, nervous system shuts down
Metabolic rate can't generate enough heat to maintain body temperature |
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Term
| Homeotherms: acclimations to cold |
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Definition
| *increase insulation: grow winter fur that they can lose in the summer, lowers T of LCT |
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Term
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Definition
C= 1/insulation
C- all factors that affect heat transfer, measure of how much heat an animal will lose
*high C= lose heat quickly, little insulation (max C is at UCT)
*low C= lose heat slowly, have a lot of insulation (min C is at LCT)
*lower min C=shallow slope --> MR will increase slowly below LCT |
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Term
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Definition
Blubber, fur
Reduces COST, lowers MR |
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Term
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Definition
| Eat more to generate more heat, MR increased by LCT lowered |
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Term
| Non-shivering thermogenesis |
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Definition
| Metabolic production of heat |
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Term
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Definition
*fat! mostly blood vessels, myoglobin, mitochondria
*use uncoupling protein to generate heat
*uncouples e- transport and proton pumps so that ATP synthesis does not occur
*proton pumps are still spinning, but because ATP isn't synthesized, just heat is produced
*used by hibernating animals, small animals, and newborns |
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Term
|
Definition
Limbs are sites of disproportionate heat loss, have no insulation, high surface area
*cool down limbs through countercurrent heat exchange (keep heat in core) in order to reduce the difference between body temp and ambient temp (thus slowing heat loss from these areas)
*cannot lower C anymore, so adjust (Tb-Ta) |
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Term
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Definition
| More cholesterol, short chain fatty-acids, unsaturated |
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Term
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Definition
homeotherm in cold environment can allow for body temperature to fall close to or equal to ambient temperature for some amount of time
*hibernation (weeks)
*daily torpor (nightly cycle)
*controlled drop in T, don't allow body to freeze
*adaptive strategy to save energy in a cold environment, especially helpful when food is scarce (night/winter) |
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Term
|
Definition
A type of temporal heterothermy in which a homeotherm will allow body temperature to fall
*bears don't really do this.
*typically only weeks long, can happen several times over a season (wake up for bathroom, etc)
*usually use energy stores to live, still metabolically active (but LOW)
*use brown adipose tissue to wake up |
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Term
|
Definition
Temporal heterothermy typical to smaller animals, birds (hummingbirds)
*generally at night when very cold
*allow body T to fall at night so that they do not use all energy stores (have very SMALL stores, high MR during night could use all & kill them) |
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Term
|
Definition
UCT is usually a few degrees below Tb
C rises, lose insulation and dissipate heat, reduce barrier for heat loss
Above UCT, generate heat that cannot be removed (lowest MR possible)
*heat loads: environmental & metabolic |
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Term
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Definition
Metabolism goes UP to create energy to lose heat
*primarily use evaporation, driving force of which is water vapor pressure difference
*efficient for removing a lot of heat (high latent heat of water means that it takes a lot of energy)
**whales: circulate blood to tongue in order to enhance heat loss as cool water washes over tongue |
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Term
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Definition
*evaporation of water, generally through sweat glands b/c skin is not usually permeable to water
*an ACTIVE process (uses E), secretion of salt and water
*best in dry environments where water vapor pressure difference is big (humidity causes problems)
*tropical animals: lose more water, less active
*COSTS: water, salt |
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Term
| Respiratory water loss (panting) |
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Definition
A lot more work than sweating, don't lose any salt
Problems: possible respiratory alkalosis
Pant at a resonant frequency, shallow breaths
*adaptations: dogs are resistant to resp. alkalosis |
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Term
| Reducing the environmental heat load |
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Definition
*long limbs to keep body away from hot earth
*posture/orientation to sun
*insulation from sun--fur, fat (camels have fat hump on back where heat is most intense, fur on back not on stomach)
*saves water from being lost |
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Term
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Definition
low Tb in morning, gradually store heat throughout day (raise Tb) instead of dissipating heat, at night dissipate heat passively as Ta cools
*most effective in large animals that can stand a large rise in Tb (can store most heat)
*for smaller animals, they can thermal cycle several times throughout the day |
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Term
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Definition
To prevent the central nervous system from overheating (brain cannot overheat), use dense network of carotid arteries and blood vessels that circulate from nasal passages (to cool down) and travel to brain (cooled arterial blood)
*in nasal passages water vapor evaporatively cools the area, so that the blood is cooled |
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Term
| Dinosaurs: evidence for homeothermy |
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Definition
| size, posture (standing is high energy), growth rates (mammal like), haversian bone canals (only BIRDS/mammals), feathers (insulation), breeding colonies, predator/prey fossil ratios, social behavior (paternal care), active/migratory |
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Term
| Dinosaurs: evidence for poikilothermy |
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Definition
*probably NOT as active, if T-rex fell it would break all bones
*gigantothermy: how could they get so warm? dissipate heat?
*haversian bone is for fast growth rates, not about homeothermy (can induce in reptiles growing fast)
*early bird fossils did NOT have haversian bones (descendants of dinos) |
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Term
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Definition
*acquire oxygen from environment (respiratory system)
*transport oxygen from surface to cell (circulatory system)
*pick up carbon dioxide from cells (circulatory)
*deliver carbon dixoide to surface for removal (respiratory system)
*majority of distance covered by convective transfer of gases, diffusion only at the cellular level
*need to enhance oxygen acquisition |
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Term
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Definition
Acquisition of gases, bringing air/water to the surface (primarily convective transfer)
*oxygen must then diffuse into the blood--easy because small distance, diffusion difficult/impossible over large distances |
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Term
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Definition
Oxygen diffuses into cell, then into the mitochondria where it is used
Equation for rate of diffusion: R=KA (P1-P2)/d
K: diffusion coefficient (depends on molecule, medium traveling)
A: surface area
d: distance
P1-P2: partial pressure difference (driving force) |
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Term
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Definition
Nitrogen: 78%
Oxygen: 21%
Carbon dioxide: .04%
Pressure measured with a barometer
1 atm= 760 mm Hg = 760 torr |
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Term
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Definition
Total pressure of a mixture of gases is equal to the sum of the partial pressures of each gas
Dry air has a partial pressure (of oxygen) of about 159 torr |
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Term
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Definition
| Water vapor takes up space and lowers the partial pressure of oxygen |
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Term
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Definition
Measured at 1 atm, 0 degrees (celsius)
Depends on T: air expands with high T, so less oxygen content
Depends on pressure: low pressure expands the volume, less unit amount/ liter |
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Term
| Concentration of gas in liquid |
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Definition
C = A (P/760)
A= absorption coefficient: vol of dissolved gas in 1 L of solution when in equilibrium with pure gas (aka solubility)
*solubility (A) drops with T and salinity |
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Term
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Definition
When water is in equilibrium with air, they have the same partial pressure of Oxygen but different concentration
*concentration in air is MUCH higher than in water |
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Term
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Definition
Air ventilated into lungs into the standing pool of air, then from here must diffuse into lungs, then the blood, then the mitochondria
**always DOWN the gradient (from high to low partial pressure of oxygen) |
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Term
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Definition
Air goes into lungs then into the blood, so partial pressure of oxygen in the lungs is relatively stable
*partial pressure of O in tissues depends
*SIGNIFICANCE: high aerobic scope (max MR - BMR) of homeotherms means that ALL systems must ramp up--increase oxygen transfer as well |
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Term
|
Definition
Use respiratory organs (lungs or gills)
Types:
*Tidal (bidirectional)- air in, air out (lungs)
*unidirectional- medium carrying oxygen moves in one direction (gills- water flows in one direction)
*random- inefficient and uncommon, based on movement (salamanders: move head/gills around in the liquid to pick up oxygen) |
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Term
|
Definition
(mammals)
*lungs with 5 lobes
*trachea- cartilage to hold it open
*alveolar sac- where exchange happens: has a dense network of blood vessels (to pick up oxygen), high surface area, very effective exchange area
*air inhaled into trachea then into bronchi then into alveoli |
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Term
| Negative Pressure: lung ventilation |
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Definition
Lungs are in the airtight thoracic cavity, surrounded by the diaphragm
*INHALATION: contract diaphragm at bottom, intercostals expand to increase the volume of the thoracic cavity which lowers the pressure and sucks in the air
*EXHALATION: diaphragm and intercostals relax, elasticity causes cavity to reduce size/volume, pressure goes up and pushes air back out
*mostly passive, ramps up during exercise (forceful inhalation/exhalation) |
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Term
| Functional aspects of tidal ventilation |
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Definition
Allows for a high aerobic scope, have a large inspiratory and expiratory reserve volume so that more oxygen can be delivered during exercise
*resting expiratory volume is lower than during exercise
*at rest oscillates between 2400 ml and 2900 ml |
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Term
|
Definition
Do not expand like mammals (very little)
*structure: trachea branches to mezobronchus, which then breaks into parabronchi, anterior/posterior secondary bronchi, and posterior/anterior air sacs
*When a bird inhales, most of it goes into the dorsal air sac, but begins to displace the old breath in the parabronchi
*Anterior air sac still retains old breath, has already been through the parabronchi |
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Term
| Fish breathing mechanisms |
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Definition
*different because water holds much less oxygen than air (lower concentration, higher viscosity, higher density)--diffusion slower
*EXPENSIVE to breathe water, about 1/5 of energy used in ventilating, and can't support high metabolic rates
*oxygen levels can fall quickly |
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Term
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Definition
*hypoxia: lower than normal levels of oxygen
*anoxia: no oxygen in water |
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Term
|
Definition
Evolutionary adaption for hypoxia/anoxia in 450 species of fish
*develop air breathing organs, like the stomach-highly vascularized to absorb oxygen that they swallow
*swimbladder
*lungs (lungfish): use tidal ventilation
*skin: absorb oxygen across skin, as long as skin stays moist |
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Term
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Definition
bag of air in the center of a fish used for buoyancy in general, but can be used for air breathing
*can be directly connected to the throat so fish swallow air and direct to swimbladder, which is vascularized (pick up oxygen) |
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Term
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Definition
| Breathes air or water, air when no oxygen in water |
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Term
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Definition
| a fish that can only breathe air |
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Term
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Definition
Larval stage: have gills (unidirectional ventilation, water) and skin absorption of oxygen
Middle stage: use skin primarily
adult: develop lungs, also use skin for oxygen absorption |
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Term
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Definition
Lungless, breathe water
low aerobic scope, low MR in general
only respiratory organ is the SKIN
small surface area for diffusion... direct blood flow to skin to pick up oxygen
At rest they can get all oxygen from the skin |
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Term
|
Definition
Ventilate much differently than mammals (positive pressure, not negative)
*No diaphragm, no thoracic cavity, less extensive rib cage
*bring a gulp of air to the throat region (buccal region) and then contract throat muscles, pushing the air down (buccal pump)
*inefficient, doesn't support high aerobic activity |
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Term
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Definition
| Use negative pressure but not the same as mammals, no separate thoracic cavity, but extensive rib cage (less of an aerobic scope possible) |
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Term
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Definition
| Shell causes thoracic cavity volume to be fixed, can't change volume for negative pressure breathing, so move limbs around in order to help |
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Term
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Definition
Soft shell turtle, vascularize skin around shell to pick up oxygen, circulate water in throat around microvilli which pick up oxygen because they are vascularized (increased surface area)
*fitroy river turtle: when river floods (annually) turtle sticks its head in the bank to prevent drowning, circulates water in and out of butt?
*pharyngeal breathing |
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