Co-ordination and response

Question 1

What happens to sweat glands when temperature rises above normal and why?

Answer 1

Sweat glands draw water out of the capillaries on the skin
sweating increases; more sweat passes up the sweat duct onto the surface of the skin
sweat evaporates off the body by using heat from the skin which causes cooling

Question 2

What happens to blood vessels when temperature rises above normal and why?

Answer 2

Blood vessels at the skin(arterioles: branches from the arteries) dilate
Blood is diverted to capillaries near the skin surface causing more blood to flow through and lose heat to the air through radiation

Question 3

How are organisms able to respond to changes in their environment?

Answer 3

Organisms have control systems. These control systems require a stimulus to operate and have:
receptors which detect the change in the environment stimulus.
effectors that execute responses to the detected stimuli