body warmed by heat generated by metabolism (humans). Body temperature independent of external environment (birds and mammals)
gains heat from external sources. body temperature is dependent on external environment. Example: invertebrates, fishes, reptiles, and amphibians.
Which is more expensive (endothermic or ectothermic) and why?
Endothermic is more expesive becuase it uses more energy.
buffers internal temperature against external fluctuations. it permits maintenace of high level of aerobic metabolism.
Balancing heat loss and gain
major effect on body temperature.
4 temperature regulation mechanisms.
radiation, evaporation, convection, conduction.
heat transfer but not direct contact
heat loss associated with water loss
movement of air or water
direct contact (feet on asvault)
endotherms also use these two things
insulation and circulatory adaptations
ectotherms and endotherms both use this
required for growth, physiological process, regulation, and reproduction.
chemical energy in food used to sustain form and function via
cataboloism and anabolism
flow and transformation of energy through animal which untimately limits animals behavior , growth, and reproduction.
energy sources and allocation
chemical energy from food used to make ATP (powers cellular work). Energetic needs of staying alive has priority over biosynthesis.
how do we examine energy sources?
amount of energy used per unit of time (often O2 consumption).
basal metabolic rate (BMR)
MR of resting, fasting, non-stressed endotherms.
how does size affect BMR?
larger animals with more mass have a higer BMR
Mass specific MR
inversely proportional to body size (oxygen epr kilogram of animals.
why is mass specific MR inversly proportional to body size?
surface area (smaller size has a greater SA to V ratio)
lose heat faster so they have a higher MR/g to generate energy (endotherm/ faster heart rate)
sleeping- metabolic rate goes down
how animals use energy to meet physiological needs. Partitioned to maintenance (BMR)
examples of energy budgets are...
Temperature regulation, activity, growth and reproduction.