Thermoregulation Flashcards
What is homeostastis?
The regulation of an internal environment in the face of changes in the external environment
What is negative feedback?
A change in a variable under homeostatic control triggers a response that opposes the change
What is positive feedback?
A change in a variable under homeostatic control triggers a response that amplifies the change
What does a sensor do in negative feedback mechanisms?
A sensor detects environmental conditions
What does an integrator do in negative feedback mechanisms?
An integrator analyzes signal from a sensor, and compares conditions to the set point and activates an appropriate effector
What does an effector do in negative feedback mechanisms?
An effector causes a physiological change that opposes the deviation from the set point
What is body heat generated by?
Metabolism
What is the rate of heat exchange called?
Conductance
Do larger or smaller organisms have lower conductance?
Larger
Why do larger organisms have lower conductance?
Because of smaller surface area / volume ratios
How do homeotherms regulate temperature?
Homeotherms maintain “constant” body temperature independent of ambient temperature.
How do heterotherms regulate temperature?
Body temperature fluctuates with ambient temperature
How do endotherms regulate temperature?
Endotherms use metabolism to generate body heat. (Internal heat generation)
How do ectotherms regulate temperature?
Ectotherms get their body heat from the environment. (external heat source)
Do ectotherms generate heat from metabolism?
Yes, they just don’t keep it!
What is ambient temperature?
Ambient temperature is the air temperature
What does thermoregulation do when in hypothermy?
Shivering, vasoconstriction, piloerection, decreasing of surface area, decreasing exposure (huddling/burrowing)
What does thermoregulation do when is hyperthermy?
Panting, vasodilation, sweating, increasing of surface area, decreasing sun exposure
What is the adaptation for heat retention?
Low conductance
What is the adaptation for heat loss?
High conductance
What are the types of behavioural regulation of conductance?
Exposure, grouping, dormancy, migration
What are the two types of dormancy?
Daily torpor, Hibernation
What is exposure?
Movement into, or out of, the sun/wind
What is goruping?
Huddling together to share radiation
What is daily torpor?
A short reduction in activity
