Thermoregulation Flashcards
What is an endotherm
Maintains their temperature within limits and can be largely independent of external temperature
What is an ectotherm
Body temp fluctuates with the external temp as cannot increase respiration to generate heat internally
What can endotherms do?
- use heat from exergonic reactions eg respiration
- increase rate of respiration
- use behavioural mechanisms
- use physiological mechanisms such as redirection blood to and from skin
What can ectotherms do?
Use use behavioural changes to maintain their internal body temp
Endotherm advantages
Fairly constant body temp despite external changes
Can be active in cool weather
Inhabit colder parts of the planet
Endotherm disadvantages
Energy from food used to maintain temp- less energy for growth means more consumption needed
Ectotherm advantages
- use less food in respiration- long periods without consumption
- used for growth in greater proportion
Ectotherm disadvantages
Less active in cooler weather- need enough food available to last them through colder seasons
What is thermoregulation?
The process whereby animals regulate body temp
Why is it so important to maintain a core body temp?
Enzymes
What is the hypothalamus involved in?
Involuntary response eg shiver
Temperature receptor s
In the skin respond to changes in the environmental temp
Mammalian skin: hairs
Erector muscles relax and the hair falls flat and allows heat loss. When the erector muscles contract hair stands upright and traps a layer of warm air insulating
Mammalian skin: skin capillaries
Blood vessels dilate so more blood goes to the surface creating more heat loss. Opposite means blood vessels constrict (vasoconstriction)
Negative feedback loop of increase in blood temp
Detected by thermo receptors
Motor neurones
Vasodilation, increase sweating, skin hairs lowered, decrease in metabolism
Normal blood temp
