37 degrees is the temperature that your enzymes work best at. Things that can affect your internal body
temperature which include energy produced in muscles during exercise, fevers caused by disease and external
temperature rising or falling.
Control of your core body temperature relies on the THERMOREGULATORY CENTRE in
your brain. Centre contains receptors that are sensitive ti temperature changes. Monitor
temperature of blood flowing through brain itself. Extra information comes from
temperature receptors in skin. They send impulses to thermoregulatory centre giving
information about skin temperature.
If temperature starts to go up the sweat glands release more sweat
which cools the body down. Sweating also makes you lose water and
mineral ions. So you need to take in more drink to replace water and
ions that have been lost. Skin always looks redder as more blood flows
through it, cooling you down.
If temperature starts to go don you will look pale
as less blood flows through skin and you lose less
energy.
If you get TOO HOT your enzymes denature and can no longer catalyse reactions in cells.
When core body temperature begins to rise, impulses are sent from thermoregulatory
centre to body so more energy is released:
Blood vessels that supply skin capillaries dilate which
lets more blood flow through capillaries. Skin flushes so
you lose more energy by radiation.
Rate of sweating goes up which cools down body as it
evaporates. IN humid weather when sweat doesn't
evaporate it is harder to keep cool.
If you get cold the rate of enzyme-controlled reactions in cells falls too low. Don't release enough
energy and cells begin to die. If core body temperature starts to fall, impulses are sent from
thermoregulatory centre to body to conserve and release more energy:
Blood vessels constrict to reduce flow of blood through
capillaries. Reduces energy released by radiation through
surface of the skin.
Sweat production is reduced. Less
sweat evaporates so less energy is
released.
You may shiver - muscles contract and relax rapidly.
Muscle contractions need lots of respiration which
releases more energy. Raises body temperature as
warm up, shivering stops.