Cold-blooded animals do not have an internal mechanism to regulate their body temperature, while warm-blooded animals maintain their body temperature by using the internal homeostasis system at a constant level regardless of the external temperature.
|Cold blooded animals||Warm-blooded animals|
|Definition||Animals that cannot consume their metabolic system to maintain body temperature are called cold-blooded animals.||Animals that maintain their homeostasis regardless of ambient temperature are called warm-blooded animals.|
|Other names||Also known as ecoterms, poikilothermal animals.||Also known as endotherms, homeothermal animals.|
|Class||Amphibians, reptiles and fish||Birds, mammals|
|Examples||Frog, Lizard||Human, polar bear|
|Etymology||Greek words (ektos: exterior), (thermo: hot)||Greek words (endo: inside), (thermos: hot)|
|Features||Less active||More active|
Cold-blooded animals are animals in which internal physiological heat sources are small or less important in controlling body temperature. These animals depend on an external environmental heat source that allows them to operate at very economical metabolic rates. These animals are laziest at night and early in the morning. When they leave their shelter, many cold-blooded animals need to warm up before starting their daily activities. In the cold season, the foraging activity of cold-blooded animals is restricted to the day in most vertebrate ectotherms and in cold climates most cannot survive at all. In lizards, for example, most nocturnal species use “sit and wait” feeding strategies. These techniques do not require as much energy as an active method and do not require hunting activity of the same intensity. Cold-blooded animals have to conserve their internal energy. Hibernation is a strategy that allows ectoderms to save energy when food is scarce. During hibernation, body temperature drops, respiration and heart rate drop, and most of the body’s metabolic functions are put on hold in a state of quasi-suspended animation. Estivation is another form of inactivity of cold-blooded animals in the summer season (Latin word: aestas meaning summer). Animals are kept in hot, dry climates. Estivation is another form of inactivity of cold-blooded animals in the summer season (Latin word: aestas which means summer). Animals are kept in hot, dry climates. Estivation is another form of inactivity of cold-blooded animals in the summer season (Latin word: aestas meaning summer). Animals are kept in hot, dry climates.
Warm-blooded animals use internal metabolic processes, environmental factors, to fluctuate overall body temperature and keep body temperature in a narrow range. Heat is generally produced from the animal’s normal metabolism, but in cold conditions, the warm-blooded animal generates additional heat by shivering. These animals have a large number of mitochondria per cell. Mitochondria allow them to produce heat by increasing the rate of fat and sugar metabolism. Warm-blooded animals must maintain their high metabolic rate by ingesting additional food. For example, a (warm-blooded) mouse should eat every day to maintain a high metabolism, while the (cold-blooded) snake should eat only once a month. Thermoregulation is also important to protect the internal enzyme system. Because as the internal temperature increases, the internal enzyme activity increases at first, but then it becomes denatured at higher temperatures and loses its physiological functions. When the internal temperature drops, hypothermia occurs and some other bodily functions are affected, so thermoregulation is important. For thermoregulation, heat can be exchanged between the animal and its environment through four mechanisms; evaporation, radiation, conduction and convection. When an animal sweats, evaporation removes heat from the skin’s surface with liquid. Radiation is the emission of electromagnetic heat waves. Heat radiates the sun and dry skin in the same way. In driving,
- The terms cold-blooded and warm-blooded are used to distinguish animals from each other.
- Cold-blooded animals show hibernation (winter sleep) and estivation (summer sleep)
- Warm-blooded animals rarely show hibernation and estivation.
- Cold-blooded animals move slowly for the regulation of
- Warm-blooded animals move fast and lose a significant amount of energy to keep their muscles warm.
- Cold-blooded animals depend on external sources to maintain
- Warm-blooded animals depend on the body’s internal system to maintain constant thermoregulation.
- Cold-blooded animals usually live in an environment of constant temperature, for example, in the tropics or in the ocean.
- Warm-blooded animals have developed several mechanisms of thermoregulation of behavior, for example, seeking shade to lower body temperature, sunbathing to increase body temperature.