So the extracellular matrix consists of organic matter as well as inorganic matter. The organic component consists predominantly of a type of protein known as collagen. And it's the collagen that gives the bone the ability to resist tensile forces, it gives the bone tensile strength. On the other hand, the inorganic component of the extracellular matrix of the bone gives our bone the ability to resist compressive strength, compressive force, and it gives the bone compressive strength. And that's because in our inorganic component of the extracellular matrix, we have crystals known as hydroxyapatite. And hydroxyapatite crystals themselves consist of calcium of phosphate as well as hydroxide ions.