The integrity of tissues is also dependent on the adhesion, by CAMs, of cells to cells and cells to the Extracellular Matrix. Extracellular matrix (ECM) All cells in solid tissue are surrounded by extracellular matrix. Both plants and animals have ECM. The cell wall of plant cells is a type of extracellular matrix.n animals, the ECM can surround cells as fibrils that contact the cells on all sides, or as a sheet called the basement membrane that cells ‘sit on’. Cells in animals are also linked directly to each other by cell adhesion molecules (CAMs) at the cell surface.