Last Lecture Gas Exchange Nutrients Digestion

Last Lecture Gas Exchange Nutrients Digestion

Outline Temperature

Phylum: Tardigrada (Water Bears)

Phylum: Tardigrada (Water Bears) -273 C (-459 F) to 151 C (304 F)

Temperature Dessert Pools 45 C (112 F), desert pupfish

Temperature Dessert Pools 45 C (112 F), desert pupfish Polar Seas -2 C (28 F), icefish

What is heat? Molecular Motion moves down thermal gradients

Temp. Importance Too Hot proteins denature Too Cold enzymes stop cell membranes are solid

Figure 2.04

Heat Balance Body Temp = heat made + heat gained - heat lost

Heat Exchange Conduction transfer through touch

Heat Exchange Conduction Convection moving air maintains thermal gradient

Heat Exchange Conduction Convection Evaporation water vapor removes heat

Heat Exchange Conduction Convection Evaporation Radiation emission of electromagnetic waves

Figure 28.01

Thermal Classification Warm Blooded versus Cold Blooded

Heat Source Ectotherm environmental heat Endotherm metabolic heat

Thermal Variability Poikilotherm temp. changes with environment

Thermal Variability Poikilotherm temp. changes with environment Heterotherm temp. changes over time (temporal)

Thermal Variability Poikilotherm temp. changes with environment Heterotherm temp. changes over time (temporal) temp. changes over body (regional)

Thermal Variability Poikilotherm temp. changes with environment Heterotherm temp. changes over time (temporal) temp. changes over body (regional) Homeotherm temp. stable

Thermoregulation Invertebrates Most Insects behavior

Thermoregulation Invertebrates Most Insects behavior Honeybees raise hive temp.: bee clusters lower hive temp.: beat wings

Thermoregulation Fishes poikilothermic ectotherms body temp. changes with environment heat from environment

Thermoregulation Fishes poikilothermic ectotherms regionally heterothermic endotherms metabolism heats part of body

Concurrent 50 % 50 % 50 % 25 % 0 % 50 % 50 % 50 % 75 % 100 % blood flow heat transfer

Countercurrent 0 % 25 % 50 % 75 % 95 % 5 % 30 % 55 % 80 % 100 % blood flow heat transfer

Figure 28.04

Thermoregulation Amphibians poikilothermic ectotherms body temp. changes with environment heat from environment evaporation limits habitats

Thermoregulation Reptiles poikilothermic ectotherms body temp. changes with environment heat from environment some thermoregulation behavior

Thermoregulation Reptiles poikilothermic ectotherms body temp. changes with environment heat from environment some thermoregulation behavior change metabolic rate evaporation

Thermoregulation Reptiles poikilothermic ectotherms body temp. changes with environment heat from environment some thermoregulation behavior change metabolic rate evaporation thermal inertia

Thermoregulation Birds & Mammals Homeothermic endotherms body temp. consistent heat from metabolism

Heat Gain & Loss Birds & Mammals evaporative water loss sweating panting

Heat Gain & Loss Birds & Mammals evaporative water loss sweating panting gular flutter

Heat Gain & Loss Birds & Mammals evaporative water loss insulation feathers, hair, blubber

Heat Gain & Loss Birds & Mammals evaporative water loss insulation countercurrent heat exchange in limbs

Figure 28.05b

Heat Gain & Loss Birds & Mammals evaporative water loss insulation countercurrent heat exchange large surface area dump heat

Figure 28.06

Heat Production Birds & Mammals Basal Metabolic Rate Shivering Thermogenesis Nonshivering Thermogenesis ATPase pump brown fat

Figure 28.07

Dormancy Sleep slight temp. decrease occurs throughout a day

Dormancy Sleep Torpor large temp. decrease occurs daily small mammals & birds cold environments

Dormancy Sleep Torpor Hibernation deep torpor last for week or months small mammals cold environments

Dormancy Sleep Torpor Hibernation Estivation large metabolism decrease hot and/or dry environments