Animals in their Climatic Environment Flashcards
Define endotherm.
Generates and controls its internal heat so that its body core temperature can be regulated at a level independent of the ambient temperature.
Define ectotherm.
Animal whose regulation of body temperature depends on external sources, such as sunlight or a heated rock surface.
Define homeotherm.
An organism that maintains its body temperature at a constant level through thermoregulation.
Define poikilotherm.
An organism that cannot regulate its body temperature except by behavioural means such as basking or burrowing.
Define hypothermia.
When core body temperature decreases significantly below normal range.
Define hyperthermia.
When core body temperature increases significantly above normal range.
Define the thermal neutral zone (TNZ).
No heat production or heat loss adjustments are required to maintain body temperature within normal core values.
List the 4 processes by which heat is transferred between animals and their surroundings.
Radiation, conduction, convection, evaporation of water.
Why is is important that animals are in their TNZ?
Utilisation of feed for growth & production is optimal as no food energy is needed to maintain core temp.
What factors affect TNZ?
- Differences in size & shape (linked to SA:V)
- Tissue and surface insulation
- Age
What are neonates at an increased risk to and why?
Hypothermia as have higher lower critical temperature zone due to small size, poor issue and surface insulation and wet birth coat (evaporation).
How do neonates survive exposure to cold?
- increasing metabolic rate
- some species activate brown adipose tissue & derive 50% required metabolic heat from non-shivering thermogenesis
- early colostrum intake (easily digested source of concentrated food energy)
What are high producing animals at increased risk of and why?
Hyperthermia e.g. Cows producing milk have a much lower critical temperature as it is a metabolically active process.
