Chapter 32 - Body Temperature (part 3) Flashcards
How do animals keep their body temperature within acceptable limits despite outside temperatures?
Thermoregulatory strategies
What are some conditions do organisms face in environmental conditions?
- temperature
- water availability
- salt/ion availability
What are the two strategies to animals use to deal with environmental variability?
- conforming
- regulating
What does is mean to be “conforming” ?
an animal’s body temperature that conforms with changes in the environment.
What does it mean to be “regulating” ?
their temperatures stay the same regardless of the outside environment
What is homeostasis?
the maintenance of a steady state despite internal and external changes
want to be in balance, in equilibrium
What is thermoregulation?
control of body temperature within an acceptable range around an ideal set point.
What happens when an organism is outside of thermoregulation?
- reduced efficiency of enzymes
- altered fluidity of cell membranes
- unacceptable speed of temperature sensitive biochemical processes
- reduces performance/fitness
- can be fatal
In one sentence, describe what thermoregulation is all about.
balancing heat loss AND
heat gain
What are the two sources of heat that animals have?
- internally - generated
- external sources
What is internally-generated heat?
its via cell respiration aka metabolism
endothermy
What are external sources of heat?
sun either directly or indirectly
ectothermy
give an example of an animal using both heat sources
manatees in Florida swim toward areas that are warmer during the winter
How do some fast moving fishes keep warm and what is this referred as?
- they generate extra body heat in cold water to keep the important tissue warm
- this is regional endothermy
What are the trade offs of endothermy? (pro vs con)
Pro- can generate enough heat to main a high core body temp in cold env.
Con - metabolically expensive so it must consume way more food than an ectotherm of the same size
What are the trade offs of ectothermy?
Pro - metabolically economical - can consume less food and can do well where food supplies are limited
Con - body temperature depends on the outside temperature. are sluggish in cold env.
what does endothermic mean?
organisms that are warmed by heat generated in their own metabolism (a stable body temperature
- birds and mammals
What does ectothermic mean?
organisms in which external sources provide most of the heat for temperature regulation
- reptiles
Why are endotherms “better” at inhabiting more environmental niches?
because they are not attached to the external environment’s temperature like birds and mammals so they can live in both hot and cold environments
Where is Earth’s greatest biodiversity at?
the equator where ectotherms thrive
What are the 4 avenues of heat exchange (aka thermoregulation) ?
- convection
- radiation
- conduction
- evaporation
What is convection and give an example
- is the transfer of heat by the movement of air or water past a surface
ex: wind takes the heat away from you - you get goose bumps
cold water current moves past you - you get cold takes the heat with it
What is radiation and give an example
- emission of waves by all objects warmer than zero
ex: sun bathing
what is conduction and give an example
- transfer of heat between molecules of objects in contact with each other
ex: sitting in a warm seat (butt transferred that heat and some is coming back)
