Topic 10-The Skin And Temperature Control

Question 0

How can blood vessels change their diameter?

Answer 0

When blood flows near the surface, heat is lost to the air. The blood vessels in the skin can widen to allow more blood to flow to the surface, or narrow to restrict surface blood flow. In warm conditions, the blood vessels open; more blood flows to the surface and more heat is lost, so that the animal cools down. In cold conditions, the vessels constrict to cut the blood flow, so less heat is lost. This does not warm the animal, but it does stop it for losing more heat. This change in the flow of blood in the skin explains why we get red in heat, but pale in cold weather.

Question 1

Name 6 parts of the structure of the skin?

Answer 1

Hair 
Erector muscle 
Sweat gland 
Sweat pore
Sweat duct
Blood vessel

Question 2

Why do the hairs stand up and lay flat in different temperatures?

Answer 2

The erector muscle in the skin can contract to raise the hairs. The air trapped between the erect hairs acts as a insulating layer, and stops the skin from losing heat. This happens in cold conditions, the raised hair/fur provides limits the heat that is lost from the skin. When it is warm, the skin needs to lose heat. The erector muscles relax, the hairs are lowered, and there is no longer an insulating layer of air. As a result, the skin will lose more heat.

Question 3

Why does the skin produce sweat?

Answer 3

In hot conditions, the skin produces sweat. When the sweat evaporates from the skin, it requires heat in order to change the liquid sweat on a vapour. This heat is drawn fro the skin, and so cools it down.

Question 4

What causes shivering?

Answer 4

There is another mechanism, not involving the skin, which warms up in cold weather.we shiver, and the heat generated by the contracting muscles warms the blood.