- ECTOTHERMS are organisms that have a limited ability to control their body temperature. Their cellular activities generate little heat. Their body temperatures rise and fall with ambient temperature changes. Most organisms are ectotherms. Examples are plants, all invertebrates, fish, amphibians and reptiles - ENDOTHERMS are organisms whose metabolism generates enough heat to maintain an internal temperature independent of the ambient temperature. Examples are birds and mammals - EXTENSION (Not really needed but anyway...) Poikilotherms are …showed first 75 words of 545 total…

…showed last 75 words of 545 total…of blood to extremities can be used to reduce heat loss with the environment Counter-current exchange: Used by endotherms in cold conditions. Blood vessels from extremities and those going to extremities are placed next to each other and they pick up heat from each other. Evaporation: Endotherms can keep cool by controlling the rate of water evaporation. Dogs pant, birds flutter a throat membrane and humans sweat. Kangaroos can lick their arms to cool themselves.