Human enzymes work best at 37ºC, so the body’s temperature is controlled.
A part of the brain called the thermoregulatory centre monitors and controls body temperature.
- It gathers information as nerve impulses from temperature receptors in:
- the brain - these are sensitive to the temperature of the blood flowing there
- the skin - these are sensitive to skin temperature
Sweating is one way to help cool the body.
We sweat more in hot conditions, so more water is lost from the body.
- This water must be replaced through food or drink to maintain the balance of water in the body.
- Ions such as sodium ions and chloride ions are also lost when we sweat.
- They must be replaced through food and drink.
- If the body’s ion content is wrong, cells can be damaged.
Temperature regulation - higher
In I/GCSE Biology, you should be able to distinguish how our body regulate our temperater under hot and cold condition!
If you become too hot or too cold, there are several ways in which your temperature can be controlled. They involve sweating, shivering, skin capillaries and hairs.
- Sweat glands in the skin release more sweat.
- This evaporates, removing heat energy from the skin.
- Blood vessels leading to the skin capillaries become wider -
- they dilate
- allowing more blood to flow through the skin, and more heat to be lost.
When we get too cold:
- Muscles contract rapidly
- we shiver.
- These contractions need energy from respiration, and some of this is released as heat.
- Blood vessels leading to the skin capillaries become narrower
- they constrict
- letting less blood flow through the skin and conserving heat in the body.
The hairs on the skin also help to control body temperature.
- They lie flat when we are warm, and rise when we are cold
- trap a layer of air above the skin, which helps to insulate the skin against heat loss.
Remember: Capillaries do not move up and down inside the skin. Temperature is regulated by controlling the amount of blood which flows through the capillaries.
And we're done with this topic! Well Done!
Drafted by Alyssa (Biology)
- "Body Temperature Regulation", https://image.shutterstock.com/image-illustration/homeothermy-homeothermic-warm-blooded-body-260nw-435142249.jpg
- "Why do I sweat so much?", https://images.theconversation.com/files/317694/original/file-20200227-24651-ykhocw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip
- "Controlling temperature". Photo from the internet.