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Thermoregulation: the basics

Applied physiology

BND Yr2

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Aims:

• To consider the importance of environment

• To define key terms

• To identify the role of the hypothalamus

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Introduction

• Sport, competitions and tournaments are held all over the world, in all types of conditions.

• Sport can occur in hot humid climates, e.g. Commonwealth Games 1998 was held in Kuala Lumpar.

• Competitions can also be held in cold, icy and snowy conditions, e.g. Winter Olympics

• Athletes need to be prepared for whatever conditions they are required to perform in.

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Introduction

• Competing in different countries puts different types of stress on the body and the way in which it functions.

• This unit will look at how these different conditions affects performance.

• It will also examine how training in different climates and conditions can help an athlete to cope more effectively.

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Thermoregulation

• ‘Thermoregulation is the process of maintaining a constant body core temperature.’ (Stafford-Brown et al. 2003)

• The body’s core includes the chest, head and abdomen.

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Thermal balance:

36°

37° 38°HEAT LOSS HEAT GAIN

In cold environment the body will loose heat

rapidly

In hot conditions the body will gain heat rapidly

The challenge is to keep this core body temperature to 37 degrees Celsius.

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Skin and Core Temperature

• The body’s skin temperature can vary greatly.

• However, if the body’s core temperature varies by 1ºC or more, it will affect the performer’s performance, both physically and mentally.

• Larger changes to core temperature can lead to either hyperthermia or hypothermia.

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Core Body Temperature

Under 36 degree Celsius

Above 38 degree Celsius

One or the other will involve risks for the performer.

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Body temperature regulation

The mechanisms that regulate temperature are activated in one of two ways:

• Thermal receptors in the skin that send a message to the hypothalamus

• Direct stimulation of the hypothalamus, by changes in blood temperature.

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Body temperature regulation

• Like a thermostat in a house, the hypothalamus regulates temperature and prevents the body from getting cold or over-heating.

• Once it receives a message that the body’s temperature is increasing or decreasing…

…it must try to put it right.