15.2 Thermoregulation in Ecotherms Flashcards
How do organisms get warmer?
-Moving: exercise, shivering
-More respiration
-Hair standing erect
-Vasoconstriction
-Move to somewhere warmer
-Convection, conduction, and radiation from the environment
How do organisms cool themselves down?
-Sweating
-Vasodilation
-Convection, conduction, radiation from environment
Definition of radiation
The transmission of electromagnetic waves to and from the air, water, or ground
Definition of Convection?
The heating and cooling by currents of the air, or water
What is the definition of conduction?
Heating as a result of the collision of molecules
What physical processes determine weather an organisms is heating up or cooling down?
-Exothermic chemical reactions
-Latent heat of evaporation: objects cool down as water evaporates from the surface
-Radiation
-Convection
-Conduction
Definition of ectotherms?
Organisms that use their surroundings to warm their bodies so their core temperature is heavily dependant on the environment
Definition of an endotherm?
Organisms that rely on their metabolic processes to warm their bodies and maintain their core temperatures
What are the characteristics of ectotherms?
-Dependant on external sources of heat
-All invertebrate animals along with fish, amphibians, and reptiles
-Low metabolic rate
-Requires less food
-Body temperature varies over time
-Less active in cold temperatures
What are the characteristics of endothermic?
-Includes mammals and birds
-Rely on their own metabolic processes to warm up
-Stable, constant core body temperature
-Capable of internal heat generation
-High metabolic rate (5X larger then ectotherms)
-Consume lots of food
What are the behavioural responses of ectotherms to regulate temperature?
-Bask in the sun, orientate their bodies so maximal surface area is exposed
-Pressing their bodies against warm ground (conduction)
-Exothermic metabolic reaction (eg. shivering)
-Shelter from sun, seek shade, hide in cracks of rocks, digging burrows
-Press their bodies against cool, shady earth or stones, move in avaliable mud, water
-Orientate their bodies so minimal surface area is exposed to the sun
-Minimise movements to reduce the metabolic heat generated
What are the physiological responses of ectotherms to regulate temperature?
-Dark colours absorb more radiation than light colours
-Alter their heart rate to increase or decrease metabolic rate
What are examples of the behavioural responses of ectotherms to regulate temperature?
-Lizards bask in the sun for long periods to get warm enough to move fast and hunt prey
-Butterflies and insects spread their wings for maximal exposure to the sun to get warm enough to fly
-Galapagos iguanas contract their muscles and vibrate increasing cellular metabolism to increase core body temperature
What are examples of the physiological responses of ectotherms to regulate temperature?
-Lizards living in colder climates tend to be darker colours so that they can get warmer
