Endotherms
- Created by: Sam Brewer
- Created on: 01-04-13 18:07
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- Endotherms
- An endotherm is an organism that can use internal sources of heat to maintain its body temperature
- Can use some of their energy intake to stay warm
- Disadvantages of being an endotherm
- A significant part of energy intake is used to maintain body temperature
- Endotherms require more food than ectotherms to survive
- A smaller proportion of food is used for growth
- Advantages of being endothermic
- Constant internal body temperature is maintained despite the external temperature
- Activity is possible at all times including the night, early morning and evening unlike ectotherms
- Endotherms are able to inhabit colder parts of the planet
- Responses used by endotherms to maintain body temperature
- Sweat glands in skin
- Sweat production reduced; evaporation rate reducees
- Lungs, mouth and nose
- Panting increases which increases evaporation
- Animal does not pant reducing evaporation
- Hairs on skin
- Hair lie flat reducing insulation- heat lost through convection and radiation
- Hair raise to create insulating layer
- Arterioles leading to capillaries in skin
- Vasodilation means more blood near the skin so heat is radiated
- Vasoconstriction reduces blood flow to capillaries so less heat radiated
- Liver Cells
- Rate of metabolism is reduced; less heat produced
- Metabolic rate increases, generating more heat
- Skeletal muscles
- No spontaneous contractions
- Spontaneous contractions such as shivering generate heat
- Behavioural mechanisms
- Moving into shade or burrow
- Moving into sunlight
- Sweat glands in skin
- Blood temperature monitored in hypothalamus
- Works on a negative feedback cycle
- Sweat production increased; evaporates cooling body
- Sweat glands in skin
- Sweat production reduced; evaporation rate reducees
- Sweat glands in skin
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