Exchange Surfaces - GCSE Biology Definition

Exchange surfaces are special areas in living organisms where substances are transferred between the inside and the outside of the body. These surfaces are crucial for processes like breathing, digestion, and waste removal. They are usually very thin, have a large surface area, and are often moist, which makes it easier for substances like gases, nutrients, and waste to pass through them quickly. In humans, examples of exchange surfaces include the alveoli in the lungs for oxygen and carbon dioxide exchange, and the villi in the small intestine for absorbing nutrients from food. These features make exchange surfaces incredibly efficient at moving important materials in and out of cells.