Cartilage derives its strength primarily from the combination of frictional resistance to water flow within its matrix and the pressurization of that water.
Cartilage, particularly articular cartilage, is subjected to significant loads, often exceeding several times a person's body weight. This remarkable ability to withstand pressure comes down to a sophisticated interplay of components within the cartilage matrix.
Here's a breakdown of how these factors contribute to cartilage's strength:
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Frictional Resistance to Water Flow: The solid components of the cartilage matrix, such as collagen fibers and proteoglycans, create a network that impedes the flow of water. When cartilage is compressed, the water within the matrix is forced to move. This movement generates friction against the solid matrix components. This frictional resistance dissipates energy and contributes significantly to the cartilage's load-bearing capacity.
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Pressurization of Water: As water is forced through the matrix during compression, the pressure within the cartilage increases. This pressurized water provides direct support against the applied load. Think of it like a water balloon; the water inside resists being compressed.
Essentially, the cartilage matrix acts like a sophisticated sponge filled with water. When a load is applied:
- Water is squeezed out.
- Friction resists this flow.
- The remaining water becomes pressurized.
These mechanisms work synergistically to provide cartilage with its exceptional strength and resilience.
