Endotherms & ectotherms
- Most animals need to maintain their core body temperature within a relatively narrow range.
- Endotherms use internally generated heat to maintain body temperature. Their body temperature tends to stay steady regardless of environment.
- Ectotherms depend mainly on external heat sources, and their body temperature changes with the temperature of the environment.
- Animals exchange heat with their environment through radiation, conduction—sometimes aided by convection—and evaporation.
Endotherms and ectotherms
Why regulate temperature?
- Radiation: Radiation is the transfer of heat from a warmer object to a cooler one by infrared radiation, that is, without direct contact.
- Conduction: Heat can be transferred between two objects in direct contact by means of conduction. Conduction of heat between your skin and nearby air or water is aided by convection, in which heat is transferred through movement of air or liquid.
- Evaporation: Vaporization of water from a surface leads to loss of heat—for example, when sweat evaporates from your skin. To learn why this is the case, take a look at the Why does sweating cool you down? video.