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28 Cards in this Set
- Front
- Back
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Physiological Ecology |
Understanding how organisms use the basic laws of physics and chemistry to meet their biological needs and solve basic physiological problems. |
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Ammonotelic |
animals who excrete ammonia as it is through urine , requires a lot of water but DOES NOT require energy |
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Ureotelic |
animals who convert ammonia into less toxic substance of urea which requires energy (ATP) for synthesis. Urea can also be stored in kidney and use by animals as an osmotically active agent , saves water |
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Uricotelic |
animals who convert ammonia into a solid substance uric acid which uses little water to eliminate and requires energy (ATP) for synthesis. Uric acid is insoluble, easily concentrated (used by birds) |
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ATP |
-synthesizes biomass -cellularwork (defending asymmetry), and external work (activity costs) -by product of metabolism or every chemical reaction |
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Ammonia |
a toxic substance produced by the animals that either must be excreted or converted into something else using either water or energy |
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Temperature |
index or measure of molecular motion (average kinetic energy) - measured in degree Celsius or Fahrenheit. Heat is TRANSFERRABLE and conduct electricity |
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Hot temperature |
High heat content, high energy content, high molecular motion and high temperature, high kinetic energy |
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Cold Temperature |
Low heat content, low energy content, low molecular motion and low temperature |
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Thermal Budget |
Heat gained from the external environment by the organism (Endogenous heat production= chemical reaction or metabolism) must be equal to the heat lost to the external environment= Body temperature CONSTANT over time --> Heat IN (metabolism) = Heat OUT (through skin surface) |
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Conduction |
-heat transfer through PHYSICAL CONTACT (solids, liquids) such as between BLOOD and ENVIRONMENT - metal has HIGH conductivity, BAD insulator - air has LOW conductivity, GOOD insulator -tissue and water have SIMILAR LOW conductivity because all life is aquatic - driving force exists as long as TEMP GRADIENT does |
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Factors influencing conduction |
1) temperature gradient b/w two objects (down concentration gradient HIGH--> LOW) if same, no net heat transfer; driving force 2) Ease of movement (physical property)- Surface area of contact (A), Length between objects (l) and composition of interface or Thermal conductivity (K) -more SA, easier transfer -shorter length, easier to transfer heat, longer-harder to transfer - high conductivity- easier to transfer heat, poor conductor or good insulator- harder to transfer heat |
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Rates of Movement Formula |
Heat Transfer through physical contact A = SA, l = Length of Objects and K = Thermal Conductivity dQ/dt = {[(K*A) / l ] * (T2 *T1) } dQ/dt = rate of change of heat content in either block 1 or block 2 (heat flow) (K*A)/ l = ease of movement (T2 * T1) = driving force [temperature gradient] NO temp gradient = NO heat flow |
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Temperature Gradient |
- Driving Force (down its concentration gradient) - Temperature of BLOOD > AMBIENT Temperature |
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Vasodilation |
- response to increase in body temperature - result of exercise -blood vessels EXPAND- SA larger- HIGH heat exchange- closer to skin, LOW distance ---> increase in heat flow from the blood through the skin out into the ambient air -dilation of blood vessel |
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Vasoconstriction |
- response to animal being too cold - diameter of blood vessel gets SMALLER--> SA SMALLER--> Distance INCREASES ( L increases)--> LESS heat transfer from circulatory system to the skin |
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Convection |
Heat transfer when environmental medium (water or air) moves over the body surface- one or both can move, warm block surrounded by air causes air to rise, - heat transfer due to both conduction between air and block as well as because air MOVED (convection) - conduction CAN MOVE |
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Free Convection |
- air or water moves BY ITSELF - moves due to temperature changes - DOESN'T move in respond to physical entity - boundary layers form - decreased driving force for heat exchange - body senses the air AROUND the body which is transferred from the animal to the environment. Therefore, air around the body is close to the body temperature - air around the animal is NOT the SAME as ambient temperature - useful on WINTER time |
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Forced Convection |
- External factors make air or water move such as fan or wind - environmental medium PHYSICALLY moved - boundary layers disrupted, body senses true environmental temperature, ex: wind chill -increased driving force for heat exchange - air around the animal is the SAME as ambient temperature - blowing fan to disrupt warm boundary layers - useful ON SUMMER DAY or HOT DAY |
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Evaporative cooling |
when water moves from liquid phase to vapor phase. Water pulls heat from the body, absorbing hear energy and cooling the body. Ex: human sweat, Panting (Dogs/Cats) -involves water LOSS - trade off - effective for heat dissipation because water absorbs energy from the body surface when it moves from liquid to vapor phase -CANNOT lead to heat gain |
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Radiation |
-Infrared Electromagnetic Radiation: longer wavelengths and less energy - Black surfaces absorb radiation (heat gain and increase of heat content in the organism) and white surfaces reflect radiation (heat loss, bounces off and has NO EFFECT to heat content to the body as it NEVER enters body) -everything that has HEAT, will radiate IER |
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Counter Current Heat Exchange between arterial blood and venal blood |
- Small driving force for heat exchange from foot to ice --> minimum heat loss to the environment, not losing heat, TRANSFERRING heat to the venous blood which will go back into the body so by the time blood reaches the foot its COLD- little heat exchange between the blood and the ice- very little heat loss- bird tolerates the cold feet because it gets warmed by next arterial blood -comes from the direction of the flow of the blood- blood flows counter current to each other -animal wants to conserve body heat and it does it by letting the feet get really cold (trade off) so it minimizes the heat loss to the environment and tolerates cold feet - HIGH SA of contact between arteries and veins -High rate of heat transfer between arterial and venous blood (arterial blood cooled and venous blood warmed) - small driving force, less heat loss |
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NO heat exchange |
- Large driving force for heat exchange from foot to ice--> significant heat loss to the environment that animal has to makeup by eating more food |
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Core Temperature |
- Birds and Mammals need to maintain core body temperature - Birds require lots of energy- extremities can get much colder than body temperature, returning blood needs to be reheated - Endotherms have high body temperature and maintain high body temperature in the coldest environments (strategy: core body temperature, maintain core body temperature (brain and heart) by letting extremities get cold |
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Why regulate body temperature? |
All chemical reactions are taking place in the body All the chemical reactions depend upon enzymes/protein Rate of chemical reaction is temperature dependent because of temperature dependency of proteins the warmer the animal is, the faster the chemical reaction will run Reaction rate and body temperature has exponential relationship- as body temp inc so does reaction rate - In critical temperature, the enzymes start to denature, the reactions start to fail, fatal situation for organisms when they reach this temperature - higher the reaction, higher MR- higher energy utilization -if reaction is slow, then animal is slow, may not be able to function in that environment -may not be able to function well, move quickly or find mates easily -trade offs between performance and energy utilization -Humans have high energy demands |
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Strategies to regulate body temperature |
1. let the temperature fluctuate with the environment (Ectotherms)- uses external heat to thermoregulate 2. maintain a constant body temperature even though the external environment varies (Endotherm) - uses endogenous heat production (MR) to maintain body temperature |
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Ectotherm |
-uses external heat to thermoregulate - cold blooded -doesn't tell you about mechanism - all non-vertebrate species (insects, crustaceans, amphibians, reptiles, fishes, sharks) -body temperature varies with ambient temperature -regulate body temperature by going into a body temperature that is suitable for them (behaviorally thermoregulate) -limited change in physiology - HUGE BEHAVIORALLY thermoregulation (putting themselves in suitable ambient temperature, lying under a rock, going out in the sun) - NO insulation (gain heat from environment, insulation makes it harder for them to get heat -LOW MR (No need to generate heat to maintain body temperature) -MR varies with ambient temperature because body temperature = ambient temperature -At low ambient temperature, MR is lower, use less energy, slower (easy prey), - At high ambient temperature, MR higher, better predator- uses more energy, trade off between energy utilization and animal function in environment -Optimal MR- MR where the trade off is right, animal functions well but less depended upon energy-less energy expenditure, occurs at a certain Optimal Temperature |
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Endotherm |
-uses internal heat to thermoregulate - warm blooded -mammals, birds, tunas, sharks -body temperature remains constant over a wide range of ambient temperature -regulate body temperature -utilize physiological thermoregulation such as vasoconstriction and vasodilation -Behaviorally thermoregulate (humans put on sweater when cold) -Insulation (conserve heat made inside body-feathers, fat, fur) -HIGH MR (high heat production) - |
