Communication and homeostasis Flashcards
What is an ectotherm
Ectotherms are not able to control their body temperature as effectively as endotherms they rely on external sources of heat and their body temperature fluctuates with the external temperature
What is an endotherm?
Endotherms use heat from metabolic reactions to maintain body temperature and is largely independent from external temperature.
What are some behaviours some ectotherms may do id they are too cold?
If ectotherms are too cold they might:
- move to a sunny area
- lie on a warm surface
- expose a large area to the sun
if ectotherms are too hot what may they do?
If ectotherms are too hot they may:
- move out of the sun
- move underground
- reduce body surface exposed to the sun
What are the advantage of ectothermy?
Advantages of ectothermy
- les of their food is used in respiration
- more of energy and nutrients gained from food can be converted to growth
- they need to fin d les food
- they can survive long periods without food
What are the disadvantages of ectothermy?
Disadvantages of ectothermy
-less active in cooler term[armatures so they are at risk from predation and cannot take advantage of food resources
What happens to enzyme controlled reactions when the body temperature falls below 10 degrees?
When the body temperature drops below 10 degrees the rate of enzyme controlled reactions falls by half
What are the advantages of endothermy?
Advantages of endothermy ;
- maintaining fairly constant temperature
- remain active even when external temperatures are low so they can take advantage of prey and escape predators
- inhabit colder parts of the planet
What are the disadvantages of endothermy?
disadvantages of endothermy:
- use a significant part of their energy intake to maintain body temperature in the cold
- need more food
- less energy and nutrients from food is used for growth
- may overheat in hot weather
What do endotherms skin do if they are too hot/too cold
too hot: -sweat glands -hair and feathers flat -vasodilation of arterioles and sphinchters too cold -less sweat -hairs a d feathers erect -vasoconstriction of arterioles and sphincters
What do endotherms gaseous exchange system do if they are too hot/cold?
Too hot
- animals panting increasing evaporation of water from the surface of the lungs and airways and this evaporation uses heat
Too cold
-less panting
What is endotherms livers do if they are too hot/too cold
too hot
-less respiration so less heat released
too cold
-increased respiration so more heat released
what do endotherms skeletal muscles do when they are too hot/too cold?
Too hot:
-fewer contractions
too cold
-shivering to release heat
What do endotherms blood vessels do when they are too hot/too cold
too hot
-Endotherms blood vessels dilate to direct blood to the extremities so more heat can be lost
too cold
-constriction to limit blood flow so blood isn’t cooled too much
What are exergonic reactions? example
Exergonic reactions release energy in the form of heat. respiration is one
