endotherm

Examples of endotherm in the following topics:

• Animal Bioenergetics

  • If an animal can conserve that heat and maintain a relatively-constant body temperature, it is classified as a warm-blooded animal: an endotherm.
  • Even with insulation, endothermal animals require extensive amounts of energy to maintain a constant body temperature.
  • Smaller endothermic animals have a greater surface area for their mass than larger ones .
  • This results in a smaller endothermic animal having a higher BMR, per body weight, than a larger endothermic animal.
  • The diet of an endothermic animal is determined by its BMR.

• Homeostasis: Thermoregulation

  • Endotherms create most of their heat via metabolic processes, and are colloquially referred to as "warm-blooded."
  • Heat is usually generated from the animal's normal metabolism, but under conditions of excessive cold or low activity, an endotherm generate additional heat by shivering.
  • Many endotherms have a larger number of mitochondria per cell than ectotherms.
  • However, endothermic animals must sustain their higher metabolism by eating more food more often.
  • Sustained energy output of an endothermic animal (mammal) and an ectothermic animal (reptile) as a function of core temperature.

• Heat Conservation and Dissipation

  • In certain climates, endothermic animals have some form of insulation, such as fur, fat, feathers, or some combination thereof.
  • Endotherms use their circulatory systems to help maintain body temperature.
  • In contrast, similar adaptations (as in dolphin flukes and elephant ears) can help cool endotherms when needed.
  • In endotherms, the circulatory system is used to help maintain body temperature, either by vasodilation or vasoconstriction.

• Evolution of Reptiles

  • It is not known whether dinosaurs were endotherms or ectotherms.
  • However, given that modern birds are endothermic, the dinosaurs that served as ancestors to birds were probably endothermic as well.

• Characteristics of Reptiles

  • This is in contrast to endotherms, which use heat produced by metabolism to regulate body temperature.
  • The advantage of ectothermy is that metabolic energy from food is not required to heat the body; therefore, reptiles can survive on about 10 percent of the calories required by a similarly-sized endotherm.

• Transferring of Energy between Trophic Levels

  • In general, cold-blooded animals (ectotherms), such as invertebrates, fish, amphibians, and reptiles, use less of the energy they obtain for respiration and heat than warm-blooded animals (endotherms), such as birds and mammals.
  • The extra heat generated in endotherms, although an advantage in terms of the activity of these organisms in colder environments, is a major disadvantage in terms of NPE.
  • Therefore, many endotherms have to eat more often than ectotherms to obtain the energy they need for survival.
  • In general, NPE for ectotherms is an order of magnitude (10x) higher than for endotherms.

• The First Law of Thermodynamics

  • The first law of thermodynamics tells us that energy can neither be created nor destroyed, so we know that the energy that is absorbed in an endothermic chemical reaction must have been lost from the surroundings.
  • We know that chemical systems can either absorb heat from their surroundings, if the reaction is endothermic, or release heat to their surroundings, if the reaction is exothermic.

• Characteristics of Birds

  • Birds are endothermic and, because they fly, they require large amounts of energy, necessitating a high metabolic rate.
  • As with mammals, which are also endothermic, birds have an insulating covering that keeps heat in the body: feathers.

• Characteristics of Mammals

  • Mammals are endothermic so hair provides insulation to retain heat generated by metabolic work by trapping a layer of air close to the body .

• Connective Tissues: Bone, Adipose, and Blood

  • Adipose tissues additionally serve as insulation to help maintain body temperatures, allowing animals to be endothermic.