Control of the Internal Environment

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Chapter 25 Control of the Internal Environment
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Homeostasis

• Maintenance of the internal environment
• Three key parts
• Thermoregulation maintaining internal
  temperatures within narrow limits
• Osmoregulation controling the gain and loss of
  water and solutes
• Excretion disposing of nitrogenous wastes

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Thermoregulation
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Thermoregulatory Adaptations

• Metabolic heat production
• Insulation
• Circulatory adaptations
• Evaporative cooling
• Behavioral responses

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1. Metabolic Heat Production
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2. Insulation
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3. Circulatory Adaptations

• Blood vessel constriction
• Blood vessel dilation
• Countercurrent heat exchange

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4. Evaporative cooling
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5. Behavioral Responses
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Energy Saving Adaptations

• Torpor state of reduced activity occurring when
  metabolic rate and/or body temperature decrease
• Hibernation
• Estivation
• Daily torpor