ENDOtherms
- Created by: Steff06
- Created on: 19-03-16 11:07
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- ENDOtherms:
- Endotherms use INTERNAL sources of heat to maintain the body temperature. They can INCREASE RESPIRATION rate to release heat and stay warm.
- Advantages of being an endotherm:
- Maintain a fairly CONSTANT body temperature regardless of external temperature.
- Activity is possible when external temperatures are COOL e.g. night and winter.
- Ability to INHABIT COLDER parts of the planet.
- Disadvantages of being an endotherm:
- A LOT of energy intake is used to maintain body TEMPERATURE in the cold.
- MORE food is required in order to grow.
- LESS energy is used for growth.
- PHYSIOLOGICAL mechanisms to maintain body temperature:
- SWEAT GLANDS - If too HIGH, secrete MORE sweat to be evaporated. If too LOW, secrete LESS sweat, LESS evaporation.
- LUNGS, MOUTH, NOSE - If too HIGH, PANTING to INCREASE evaporation. If too LOW, NO panting, so LESS evaporation.
- HAIRS on skin - If too HIGH, hairs lie FLAT, LITTLE insulation, MORE heat LOST. If too LOW, hairs RAISED to TRAP HEAT.
- ARTERIOLES - If too HIGH, VASODILATION, MORE blood near surface. If too LOW, VASOCONSTRICTION to REDUCE blood flow near skin.
- LIVER cells - If too HIGH, METABOLIC rate REDUCES, LESS heat generated. If too LOW, METABOLIC rate INCREASES, MORE heat generated.
- SKELETAL muscles If too HIGH, NO spontaneous CONTRACTIONS, if too LOW, spontaneous CONTRACTIONS e.g. shivering to generate MORE heat.
- BEHAVIOURAL mechanisms to maintain body temperature:
- Too HOT:
- Move into SHADE/ hide in burrow.
- Orientate body to DECREASE SA exposed to sun.
- Remain INACTIVE + spread out limbs to INCREASE SA.
- Too COLD:
- Move INTO sunlight.
- Orientate body to INCREASE SA exposed to sun.
- MOVE about to generate HEAT in muscles.
- Too HOT:
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