Species: rat (Rattus norvegicus; mammal).
Technique: hematoxylin-eosin and Alcian blue in 8 µm paraffin sections.
The fibrous cartilage is found in intervertebral discs, in some joints, at the insertion point of the tendons in the bone epiphysis, in parts of the heart valves and in the penis of some animal species. The fibrous cartilage is usually surrounded by hyalin cartilage and lacks perichondrium. It shows mixed properties found in the dense connective tissue and in the hyalin cartilage. Actually, the fibrous cartilage cells can share features with chondrocytes and fibroblasts, and it is difficult to distinguish what type of cells they are. Generally, in the deeper parts of the fibrous cartilage, cells are more similar to chondrocytes, whereas those more superficial are like fibroblasts. The ultrastructural features of inner cells are similar to those observe in chondrocytes. Fibrous cartilage cells can be distributed irregularly and more scattered than in the hyalin cartilage, but they can also be arranged in cords. This cartilage type is less elastic than hyalin cartilage, but more than tendons. Depending on the location in the body, the fibrous cartilage is formed from pre-cartilage, from hyalin cartilage or from fibrous connective tissue.