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What is the optimal temperature range? Mammals C ; Birds C Amphibians & Reptiles: varies greatly Thermoconfomers: Fish: within 1-2 C of surrounding water Invertebrates: with some exceptions (bees)
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Big Idea #2:Cellular Processes and
CommunicationBiological systems utilize free energy and molecular building blocks to grow, to reproduce, and to maintain dynamic homeostasis.
Questions to ponder…What is human body temperature in
Celsius?Is there an average body temperature for
animals?How does the body use feedback order to
maintain a constant body temperature?Can we connect properties of water to
thermoregulation?
What is the optimal temperature range?
Mammals 36-38 C ; Birds 39-42 CAmphibians & Reptiles: varies greatlyThermoconfomers:
Fish: within 1-2 C of surrounding water Invertebrates: with some exceptions (bees)
Role of Water PropertiesDefine
High specific heat? Explain in terms of the
structure of water.
Apply
Air vs. water temp?Connect to marine
vs. land animals?Role in daily and
seasonal change?Animal adaptations?
EctothermsHeat transfer
occurs easilyMetabolic rate has
little effect on body temperature
Invertebrates, fishes, amphibians, reptiles
Endotherms Body warmer
than the environment
Due to high metabolic rate
Birds, mammals, bees and moths
Why aren’t they called cold blooded or warm-
blooded?
Who has an advantage? Endotherms
Can perform vigorous activity for long periods of time.
Can tolerate winter and hot environments
Ectotherms: Cost of food Human: Metabolic
resting rate of 1300 kcal/day
Alligator: Metabolic resting rate of 60 kcal/day
Investigating a Negative Feedback Loop
StimulusSensorSet PointResponseNegative Feedback
Evaporative Cooling Panting, Sweating,
Bathing Water absorbs heat when
it evaporates which has a cooling effect. Summer topor: low
metabolism due to high temperatures
Daily topor: animals go inactive when temperature isn’t ideal
Vasodilation/Vasoconstriction
Vasodilation: increase in the diameter of superficial blood vessels (cools)
Vasoconstriction: decrease in the diameter of blood vessels (warms)
Metabolic Change Movement, shivering
increase muscle contraction.
Heat is a waste product of metabolism
NST (nonshivering thermogenesis)
Brown Fat: tissue specialized for using mitochondria for heat production instead of ATP
Human Thermoregulation
Formative Assessment
Formative AssessmentPart of Feedback Loop? Cross country skiing on a
warm day. You have dressed in layers and you have just climbed your first incline.
Part of Feeback Loop? Oops…you didn’t dress
for the weather. You are out cross country skiing and stopped to take a break. Suddenly, clouds cover the sky and the wind picks up. You have forgotten your hat and gloves.
What is postive feedback then?
Does positive feedback happen?
Let’s look at an example with water and climate change.
More feedback loopsPreview the role of
the thyroid:
How does the brain and the thyroid control metabolism?
How does the thyroid and parathyroid control blood calcium?
More on Water PropertiesFor each property of water:
Description Structure Meets Function
Implications
What is the property?
How does the structure of water cause this property?
How does this impact life on Earth?-At the organism level?-At the ecological level?