Figure 74

Electron micrograph of a young, active chondrocyte and surrounding matrix. The nucleus (N) of the chondrocyte is eccentrically located, like those in Figure 7.3, and the cytoplasm displays numerous and somewhat dilated profiles of rER, Golgi apparatus (G), and mitochondria (M). The large amount of rER and the extensive Golgi apparatus indicate that the cell is actively engaged in the production of cartilage matrix. The numerous dark particles in the matrix contain proteoglycans. The particularly large particles adjacent to the cell are located in the region of the matrix that is identified as the capsule or territorial matrix, xl5,000. (Courtesy of Dr. H. Clarke Anderson.)

A firmly attached connective tissue, the perichondrium, surrounds hyaline cartilage

The perichondrium is a dense connective tissue composed of cells that are indistinguishable from fibroblasts. In many respects, the perichondrium resembles the capsule that surrounds glands and many organs. It also serves as the source of new cartilage cells. When actively growing, the perichondrium appears divided into an inner cellular layer, which gives rise to new cartilage cells, and an outer fibrous layer. This division is not always evident, especially in perichondrium that is not actively pro-

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