1. Temperature control
• All: Why is it important to maintain your
body temperature.
• Most: How your body stops you from
getting too hot/cold.
• Some: How other animas reduce heat
loss.
3. The Inuit people live on
the Arctic coasts, for
example parts of
Greenland, Siberia,
and Alaska.
4. Average temperatures in the far north of Alaska range
from –30 °C in winter to 2 °C in summer. Further south
the temperature range is –12 °C to 15 °C.
7. Why control temperature?
The body must be kept at a constant
temperature of 37 °C. Why?
Optimum temperature for the
body’s enzymes. Even slight
changes in body temp can have a
life-threatening effect on health.
Too low - reactions become too slow for cells to survive
Too high - body’s enzymes are at risk of denaturing.
10. How is temperature controlled?
Body temperature is monitored and controlled by temperature
receptors in the skin and brain (thermoregulatory centre)
These receptors detect changes
in the temperature of blood Thermoregulatory centre
flowing through those areas.
If body temperature deviates from 37
°C, these receptors send out electrical
signals to the thermoregulatory centre
that trigger actions that increase or
decrease heat loss.
11. How is temperature controlled?
1. Control of temperature relies on receptors.
Where are temperature receptors located?
2. What do these temperature receptors do?
3. Why does skin appear red when we are hot?
4. Why do we drink more in hot weather?
12.
13. Keeping warm/cool
How can heat be gained?
shivering
vasoconstriction
wearing extra clothing.
How can heat be lost?
sweating
vasodilation
removing extra clothing.
Editor's Notes
Teacher notes This three-stage animation can be used to introduce the concept of homeostasis in terms of responding to change in external conditions.
Teacher notes See the ‘ Enzymes ’ presentation for more information on enzymes and denaturing.
Teacher notes This five-stage animation illustrates what would happen to a boy and girl in extreme environmental conditions who are unable to thermoregulate. The girl is unable to vasodilate or produce sweat to help cool her down, which speeds up the rate at which she develops heatstroke. People who have anhidrosis – an absence or severe reduction of sweating – have a dangerously high risk of heatstroke in hot weather, which can rapidly be fatal if untreated. In a person who can thermoregulate, sweating will lead to dehydration in extreme heat, which results in additional heatstroke symptoms to the ones shown in the animation.
Teacher notes This two-stage animation introduces the physiological and behavioural mechanisms of thermoregulation.
