Posts Tagged ‘Thermoregulation’

A Border Collie resting during a game of fetch.

Image via Wikipedia

Animals like dogs use panting, rather than sweating, as their main method of reducing their body temperature.
Panting is not the same as fast breathing as panting is very shallow – very little air is taken into the gas-exchange parts of the lungs during panting.

So how does panting work to reduce body temperature?

  • The dog dilates the blood vessels to the tongue and increases its heart rate – this ensures that warm blood is pumped away from the body core and arrives at the surface of the tongue.
  • The tongue is made flatter and thinner to increase it’s surface area.
  • The tongue is moist as it has a layer of saliva (not sweat!) on its surface.
  • Air is passed quickly backwards and forwards over the surface of the tongue and, in the process, the moisture (saliva) begins to evaporate.
  • Evaporating moisture has a cooling effect, it carries the heat from the blood vessels in the tongue┬áinto the air.
  • This leaves behind cooler blood in the capillaries of the tongue which is then carried back into the body to reduce the core temperature.