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internal and external communication systems

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Outline the need for communication systems within

External environmental changes are changes in the external environment which

can cause stress. it may change slowly so there will be a gradual response. it

may be a quick change so a rapid response is needed.

Internal environmental changes are that the environment of internal cells is that

they are protected by epithelial cells and they are bathed in tissue fluid. the

activities of cells alter their environment for example, by releasing toxic products

that need to be removed. the co-ordination of activites of organs are that there are

groups of specialised cells to form tissues and organs. The cells monitor the blood

and can release a substance into the blood to remove certain substances.

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