co-ordination and response Flashcards
what happens in vasoconstriction?
- muscle cells in the walls of the arterioles contract
- causes constriction of blood vessels
- less blood flows through capillaries in the skin
- less heat can be lost by radiation
- skin appears pale
what happens in vasodilation?
- muscle cells in the walls of the arterioles relax
- causes dilation of blood vessels
- more blood flows through capillaries in the skin
- more heat can be lost by radiation
- skin appears red
what do reflex arcs do?
- control reflex reactions
- make fast, automatic responses
- stop serious damage
what does homeostasis allow animals to do?
control the internal environment of their bodies
what does homeostasis do?
keeps conditions constant
what is controlled in homeostasis
- water content
- body temperature
where is adrenaline made and what are the effects?
- made in the adrenal glands
- makes the heart beat faster
where is insulin made and what are the effects?
- made in the pancreas
- causes liver + muscles to take up glucose (to keep blood glucose levels normal)
where is testosterone made and what are the effects?
- made in the testes
- controls development of male sex organs
where is progesterone made and what are the effects?
- made in the ovaries
- maintains the lining of the uterus
where is oestrogen made and what are the effects?
- made in the ovaries
- controls development of female sex organs and causes uterus lining to get thick and spongy
what is thermoregulation?
the ability to control body temperature
what is our average body temperature?
37ºc
what are the positive of maintaining are body temperature ?
it allows humans to be active in a range of external activities
how do we conserve heat in the cold?
wear more clothes
