Zusammenfassung der Ressource
Thermoregulation - GCSE Biology
- Vasoconstriction
- Occurs of core body temp. starts to fall
- Smooth muscle in arteriole walls contracts
- Arteriole constricts
- Less blood flows through capillaries
close to the surface of the skin
- Blood is redirected through
shunt vessels in lower levels of
the skin
- Reduces the rate of heat loss from the body
- Vasodilation
- Occurs if core body temp. starts to rise
- Smooth muscle in arteriole walls relaxes
- Arteriole dilates
- More blood flows through capillaries close
to surface of skin
- Increases rate of heat loss from the body
- Goosebumps
- Occurs when core body temp. starts to fall
- Each hair has a tiny muscle attached to the base
- This is called the Pili erector muscle
- The muscle contracts and
the hair is pulled upwards
- This traps an insulating layer of still air
- This reduces the rate of
heat loss from the body
- Shivering
- Occurs when core body temp. starts to fall
- Muscles require energy to contract
- This energy is supplied by respiration
- During respiration some energy
is always lost as heat energy
- During shivering, the muscles contract repeatedly
- The rate of respiration increases, and heat is generated
- This reduces the rate of heat loss from the body
- Sweating
- Occurs if core body temp. starts to rise
- Glands in the skin start to produce sweat
- Water in the sweat evaporates
- In order to do this, it must
absorb heat from the body
- Increases the rate of heat loss from the body