Temperature Regulation (E2) Flashcards
Regulator
an animal that uses internal mechanisms to control internal change in the fact of external fluctuation
Conformer
an animal that allows its internal condition to change in accordance with external changes
Homeostasis
a constant internal environment, even when the external environment fluctuates
Negative feedback
a control mechanism that dampens the stimulus
Positive feedback
a control mechanism that amplifies the stimulus
Thermoregulation
the process by which animals maintain their body temperature within a normal range, temperatures outside normal range reduce the efficiency of enzymatic reactions
Integumentary system
the outer covering of the body (skin, hair, nails maybe claws or hooves)
Endothermic
animals warmed by heat generated by metabolism
Can maintain a stable body temperature even in the face of large fluctuations in environmental temperature
Ectothermic
gain most of their heat from external heat
Adjust body temperatures by behavioral means (seeking shade, basking in sun)
Consume less food than endotherms of similar sizes
Poikilotherm
an animal whose body temperature varies with the environment
Homeotherm
an animal with a relatively constant body temperature
Heat loss and heat gain processes
Radiation - emission of electromagnetic waves by all objects
Evaporation - removal of heat from the surface of a liquid that is turning to gas
Convection - transfer of heat by movement of air or liquid past a surface
Conduction - direct transfer of heat between objects in contact with each other
Insulation
reduces the flow of heat between an animal’s body and its environment
Circulatory Adaptations
route for heat flow between the interior and exterior of the body
Vasodilation - a widening of blood vessels near the body surface, increases blood flow
Vasoconstriction - reduces blood flow near the body’s surface
Countercurrent exchange - the transfer of heat or solutes between fluids that are flowing in opposite directions
Cooling by Evaporative Heat Loss
Water absorbs heat when it evaporates
Sweat glands secrete water, which carries heat away from the skin
Panting also allows water to carry away the heat from the body
Behavioral Responses
control of body temperature through behavioral responses to changes in the environment
When you’re cold, you seek warmer places
When hot, you bathe or move to cool areas
Adjusting Metabolic Heat Production
Thermogenesis - heat production
Thermogenesis can be increased by muscle activity (shivering)
Non-shivering thermogenesis takes place throughout the body, causing mitochondria to increase metabolic activity, producing heat instead of ATP
Acclimatization
Acclimatization to seasonal temperature change includes adjective insulation (growing thicker fur, shedding fur)
Hypothalamus
a concentration of sensors responsible for thermoregulation, a region of the brain
