HEAT TRANSMISSION: Temperature regulation in the human body is extremely important as it must be maintained at 37°C, as mentioned before. There are four methods of heat transfer both in and out of the human body to maintain this temperature:
• Conduction – heat directly being transmitted through an object due to difference in temperature or electrical potential • Convection (sensible heat) –movement in circular motion of heat in one region to another
• Radiation – emission of heat energy waves or particles
BMS1031 -‐ Lisa Hai My Do
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Latent heat (evaporation/conduction)-‐ the conversion of solid state into liquid state or liquid state to vapour state
Figure1 “The four forms of heat transfer” http://www.fao.org/docrep/008/y7223e/y7223e09.htm
RESPONSES TO HIGH TEMPERATURE: When your body is exposed to extremely high temperatures, it must regulate itself to maintain a stable internal temperature and hence must transfer the excessive heat to the environment utilising the four heat transfer mechanisms. The human body can either increase the conduction rate or the transfer rate to elevate the rate of heat transmission; where the rate of conduction is the movement of heat from core to surface and the rate of transfer is the movement of heat from surface to environment. The rate of conduction is dependent on the dilation and contraction of vessels, while perspiration, clothing option, external temperature and level of activity affects the transfer rate.
Sdsdssssss – Latent Heat of the body: When the external temperature is greater than 37°C, sweat glands are simulated by sympathetic cholinergic fibers and epinephrine in the blood. The sweat then evaporates