Yes, cartilage needs oxygen to function, but it receives it differently than most tissues.
How Cartilage Gets Oxygen
Cartilage is unique because it is an avascular tissue, meaning it doesn't have its own blood vessels. This is different from most other body tissues that rely on blood vessels for direct oxygen delivery. Instead, cartilage relies on a process called diffusion.
- Diffusion from Synovial Fluid: Oxygen is supplied to cartilage by diffusion from the synovial fluid. This fluid surrounds the cartilage in joints and is the source of oxygen and nutrients.
- Oxygen Tension: The oxygen tension in cartilage varies. According to the provided reference, it ranges from 9% near the surface to 2% deeper within the cartilage. This is much lower than the 21% oxygen level typically found in the air and in most cell culture environments.
Cartilage Metabolism and Low Oxygen
The cells in cartilage, called chondrocytes, are adapted to function in these low-oxygen environments.
| Feature | Description |
|---|---|
| Vascularity | Avascular; lacks blood vessels. |
| Oxygen Source | Diffuses from synovial fluid. |
| Oxygen Levels | Ranges from 9% to 2%, lower than typical atmospheric oxygen levels (21%). |
| Adaptation | Chondrocytes are adapted to function in low-oxygen conditions. |
Practical Insights
- Cell Culture Studies: The fact that cartilage cells are adapted to low oxygen has implications for research. When cells are grown in laboratories, the usual 21% oxygen environment does not accurately reflect the in-vivo (living) conditions for cartilage cells.
- Implications for Health: Understanding how cartilage receives oxygen is critical for developing better treatments for joint injuries and arthritis.
