Keeping conditions constant is called equilibrium or homeostasis. When a system is balanced, it has
equilibrium.
Certain things must be balanced for living organisms to survive; such as: temperature and water in cells.
Equilibrium is often maintained by a feedback mechanism. In a feedback mechanism, the level of a
substance affects the release of another substance or the activity of an organ.
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Controls blood pressure – when blood pressure rises, a message is sent to the brain
which signals the heart to slow down, decreasing blood pressure.
Proper chemical balance – Insulin (chemical hormone) is released when levels of blood
glucose rise.
Regulates breathing rate – when to much carbon dioxide is in your blood stream your
respiratory system gets a signal to breathe faster.
Sweating helps maintain body temperature
Animals respond to internal stimuli such as hunger and thirst to maintain equilibrium of water and
nutrients.
Plants regulate the amount of water loss by the opening and closing of microscopic openings in their
leaves.
Turgor pressure is the pressure of the water within plant cells. If plants don’t have enough water, they
will lose turgor pressure and wilt.
Plants sometimes maintain equilibrium with a growth response, such as growing toward the light.
A signal that causes an organism to react in some way is called a __________________.
A plant grows toward the light. The plants action is an example of a _______________.
A grapevine coiling around a fence post is an example of ____________________.
The process by which an organism’s internal environment is kept stable in spite of changes in the
external environment is called _______________________.
One way that sweating helps to maintain homeostasis is by ______________________.
Which body systems maintain homeostasis?