What is the internal environment and explain how it is related to the inside of a cell, the interstitial fluid and to the outside world?

Internal environment and its relation with inside cell

Explanation:

Internal environment of an organism is water-based where the body cells exist. The fluid known as tissue fluid washes the body cells. Oxygen and nutrients are carried to the cells from Internal Transport system of the body. Interstitial fluid is found in between the spaces of cell. It comes out from the substances that flow out from the blood capillaries. Oldertissue fluid is replaced by new fluid where older flood drains towards lymph vessels.