What are extracellular fluids?

Extracellular fluids refer to all body fluids located outside of the cells. This includes fluids found in various compartments such as blood plasma, interstitial fluid, lymph, and transcellular fluid. The primary function of extracellular fluids is to provide a medium through which nutrients, oxygen, and waste products can be exchanged between the cells and their external environment.

In contrast, body fluids found within cells are classified as intracellular fluids, which primarily consist of cytosol and are critical for various cellular processes. Options related to fluid in the digestive system and those removed during dialysis do not accurately define extracellular fluids, as they pertain to specific contexts or processes rather than the general classification of fluid outside of cells. Therefore, the definition encompassing body fluids that exist outside of cells is the comprehensive and correct choice.