Temperature 1 Flashcards
Heat
Thermal energy, W
-heat energy can be transfered
Temperature
- relative measure of thermal energy
- heat follows a temperature gradient; HEAT FLUX (temp gradient)=rate of heat transfer
ambient/environmental temperature (Ta)
- thermal niche for an animal
- niche temp. fluctuates over tide, such as in a tide pool
- temp. varies within a niche and animal movement
body temperature (Tb)
- temp. of an animal
- Tb fluctuates over time and place
- Tb varies for different parts of body
variability of ambient/environmental temperature
- aquatic environments provide less extreme and less variable temperatures
- deepsea +4C
- ocean surface tropical: +35, polar: -2
- intertidal varies from -20 to +35
- rivers and lakes from 0 to 35
- hot springs at +40C
- alpine air, -60, desert air +60
at +60C….
proteins denature, animals die
heat loss by conduction
-transfer of thermal energy within and between media; usually via contact
heat loss by convection
-loss to a MOVING FLUID: breathing air/water, wind chill, U^2
heat loss by evaporation
heat needed to convert liquid water to vapor, such as in sweat or drying
=520 cal/g; 2.2 kJ/g
heat gain by radiation
-transfer of thermal energy by means of electromagnetic radiation
heat flux
- rate of heat energy movement
- (thermal conductivity)*(temperature gradient)
- DISTANCE=creates insulation
- SURFACE AREA=body shape; respiratory organs
- BODY MASS=2pir vs. pir^2
Thermal conductivity
ability of heat energy to MOVE within and between an object(s)
-ie. thermal conductivity of ice is greater than water, which is greater than air, and rocks conduct better than muscle
heat capacitance
- ability to STORE heat energy
- water is 3000x greater than air for storage
- thermal conductivity and heat cap are large determinants of Tb
aquatic environments have less extreme and less variable temperature because…
- high heat capacitance/storage of water
- limited solar influence of and limited mixing in water
- its maximum density @ 4C, meaning it is difficult to go below 4C without supercooling
why is thermal physiology so important?
- temp determines rate of reactions
2. animals have evolved an elevated, regulated, and more narrow Tb starting 200 mya
