Kõhrrakud

Kõhrrakud, also known as chondrocytes, are specialized cells found in cartilage. They are derived from mesenchymal stem cells and are responsible for producing and maintaining the cartilaginous matrix. This matrix is composed of collagen fibers, proteoglycans, and water, which gives cartilage its unique properties of flexibility and resilience.

Chondrocytes reside within small cavities called lacunae, scattered throughout the extracellular matrix. They exist in relative isolation, though they can communicate with each other through gap junctions. The primary function of chondrocytes is to synthesize and secrete the components of the cartilage matrix, a process that is crucial for tissue repair and maintenance. They also play a role in the development and growth of cartilage.

There are different types of chondrocytes, often classified by their location and function within the cartilage. For example, in growing long bones, chondrocytes in the proliferative and hypertrophic zones of the growth plate are involved in endochondral ossification, the process by which bone replaces cartilage.

Cartilage itself is an avascular tissue, meaning it lacks blood vessels. Consequently, chondrocytes rely on diffusion from surrounding tissues or synovial fluid for nutrient and oxygen supply, and for waste removal. This limited diffusion contributes to the slow healing capacity of cartilage injuries. Diseases affecting cartilage, such as osteoarthritis, often involve the degradation of the extracellular matrix and the dysfunction or loss of chondrocytes. Understanding the biology of kõhrrakud is essential for developing treatments for these conditions.