module 3 b34 Flashcards
Behavioural, biochemical, and physiological responses that ensure body temperature (TB) is within an acceptable limit
thermal strategy
Temperature of the animal’s surroundings
Ambient temperature: TA
Most important environmental influence on animal’s thermal strategy
Body temperature is allowed to vary with ambient temperature
tolerance
Body temperature does not vary with ambient temperature
regulation (us humans exhibit this)
what are the two thermal strategies
regulation and tolerance
physical contact between something that is warm and something that is cold
conduction
movement of fluid around us
convection
transfer of thermal energy between an object and an external medium that is moving
Convection
emission of electromagnetic radiation
Radiation
rate of heat transfer (from hotter to colder)
heat flux (Q)
what is the units for heat flux (rate of heat flow)
Watts
Layer of material that reduces thermal exchange
insulation
Internal insulation (under the skin)
blubber
external insulation
hair, feathers, air, water
Large animals exchange heat more (SLOWLY OR FASTLY) than small animals
SLOWLY
Animals living in cold environments tend to be larger
Bergmann’s Rule:
Animals in colder climates have smaller extremities (outer parts)
allen’s rule
- not necessarily true
- animals living in smaller extremities still have big ears for example
variable body temperature
poikilotherm
stable body temperature
homeotherm
produce heat internally, animal generates internal heat to maintain body temperature
endotherm
heat comes from external sources, environment determines body temperature
ectotherms
hypermetabolic phase accompanied by a decrease in body temperature
- ex hiberation, torpot
Temporal endothermy
optimal range for physiological processes; metabolic rate is minimal
Thermoneutral zone
Metabolic rate increases to increase heat production
lower critical temp (LCT)
Metabolic rate increases as animal induces a physiological response to prevent overheating
upper critical temperature (UCT)
maximum range of temperatures in which individuals can survive
Survival zone
Refers to the range of environmental conditions (e.g., temperature, pH, salinity) in which an organism can survive.
tolerance zone
Prescriptive Zone:
Refers to the specific range of environmental conditions that are actively selected by organisms when they have the ability to move or choose.
It reflects the preferred or ideal conditions for an organism’s survival and functioning.
Prescriptive Zone:
Ambient temperature at which 50% of animals die
incipient lethal temperature
can tolerate a wide range of ambient temperatures
Eurytherm
- us humans
can tolerate only a narrow range of ambient temperatures
Sternotherm
Body temperature varies in regions of the body
regional heterotherms
Maintain membrane fluidity at different temperature by changing membrane lipids. cholesterol content
homeoviscous adaptation
remodeling of the membrane
animals that thrive at low temperatures
Psychrotrophs
behavioural and physiological mechanism to prevent ice crystal formation
Freeze-avoidance
animals can allow their tissues to freeze in a controlled, safer way
Freeze-tolerance
Proteins or glycoproteins that depress the freezing point by non colligative actions
Disrupt ice crystal formation by binding to small ice crystal and prevent growth
anti freeze molecules
the internal thermostat in mammals is located where
hypothalamus
the internal thermostat in birds is located where
spinal cord
Shivering thermogenesis is unique to
birds and mammals only
uncoordinated myofiber contraction that results in no coordinated net muscle work
Shivering thermogenesis:
is a physiological state of decreased metabolic activity in animals, characterized by reduced body temperature, heart rate, respiration, and energy expenditure. It is a survival strategy that allows animals to conserve energy during periods of extreme environmental conditions, such as cold temperatures or food scarcity.
torpor
