Homeostasis

Question 1

Define homeostasis:

Answer 1

The maintenance of a constant internal environment.

Question 2

Give 3 processes that happen when someone is too cold:

Answer 2

-Hair stands on end
-Less sweat released
-Vasoconstriction

Question 3

Define vasoconstriction:

Answer 3

Arterioles supplying the capillaries near the surface of the skin get narrower - they constrict. Less blood will flow through, therefore less heat is lost by radiation.

Question 4

Give 3 processes that happen when someone is too hot:

Answer 4

-Hair lies flat
-More sweat is released
-Vasodilation

Question 5

Define vasodilation:

Answer 5

Arterioles supplying the capillaries near the surface of the skin get wider - they dilate. More blood will flow through the capillaries near the surface of the skin, therefore more heat will be lost by radiation.

Question 6

How does hair standing on end help warm someone up when they’re cold?

Answer 6

The hairs trap a layer of air which provides insulation for the conduction of heat.

Question 7

How does hair lying flat help cool someone up when they’re hot?

Answer 7

Hair lies flat and therefore an insulating layer of air is not formed.