Regulation of Body Temperature Flashcards
What is radiation?
Heat transmitted via emitted electromagnetic waves (infrared heat rays). all objects emit this.
Conduction
heat transfer by conduction occurs within a solid or between two or more solids in close contact
What is an example of something that changes conduction
clothing (wet clothing increases conduction of heat and increased heat loss)
Convection
heat transfer by this method occurs in a fluid or between a fluid (gas) and a solid, providing a temperature gradient exists.
How does convection differ from conduction?
Convection differs from conduction in that the fluid or gas can be moving and therefore heat is transferred and displaced.
Evaporation
Heat transfer occurs by means of a change in state, eg. from a liquid to a gas
What is the most efficient way for the body to lose heat?
evaporation (sweating)
What factors in the air affect evaporation?
dry area increases evaporation; humid air decreases evaporation
What is the zone of thermal neutrality?
the range of ambient temperature in which the body maintains its heat balance without increasing either heat production or loss above their minimum level
the higher the ratio of surface area to volume, the ____ the heat loss
greater
Why do you curl up when you are cold?
lower surface area of the body leads to less heat loss
the lower temperature of the extremities in a windless environment reflects a ______ SA/V ration of the limb relative to the trunk
large (ex: a rabbit’s ears are big and lower temp relative to the trunk)
What part of the body controls temperature?
the hypothalamus (“brain’s inner thermostat”)
if the body core is too hot, the _______ tells the body to _____
hypothalamus, sweat
if the body core is too cold, the ____ makes the body _____
hypothalamus, shiver
