2.88 - Skin temperature regulation

2.88 describe the role of the skin in temperature regulation, with reference to sweating vasoconstriction and vasodilation

A section of the skin 

We are warm blooded. This means that we can keep our body temperature constant all the time. 
Warm blooded animals have fur or hair which traps a layer of air close to the skin. Air is a poor conductor of heat so it cuts down the amount of heat lost. 


In cold weather the hairs stand up. They do this when the hair muscles contract, this traps a thicker later of air so it cuts down even more on the heat loss. 
In hot weather the hair lies flat. The hair muscles are now relaxing so less air is trapped close to the skin and more heat is lost by radiation. 

 Your body temperature is monitored by your brain, it monitors it by the blood running through it. 


When it is hot: 
Blood Vessels at your skin surface widen. They allow more blood to flow to the surface. So more hear is lost by radiation. 
Sweat Glands in your skin make sweat. The sweat evaporates and this cools you down.


When it is cold: 
Blood Vessels at your skin surface close up. They cut down the flow of blood to the surface. So less hear is lost by radiation.  
Sweat Glands stop making sweat 
Shivering, your muscles start to contract quickly. This produces extra heat that warms your body. 

Vasodilation: The dilatation of blood vessels, which decreases blood pressure.

Vasoconstriction: The constriction of blood vessels, which increases blood pressure.