Cartilage is a specialized, semi-rigid connective tissue characterized by the predominance of a glycosaminoglycan and proteoglycan-rich ground substance that attracts water, giving this tissue a high degree of hydration. The extracellular matrix contains varying amounts and types of connective tissue fibers, giving rise to three main types of cartilage: hyaline, elastic, and fibrocartilage. Compare and contrast the properties and functions of the three types of cartilage as described in the table below.

Hyaline cartilage, the most common type of cartilage, contains the smallest proportion of fibrous material in its abundant ground substance. As its name implies, it is glassy or translucent in appearance due to the properties of its extracellular matrix. Examine the cartilage in the trachea and in this trichrome stained slide of the larynx.

In these slides and as shown in the image at the right, identify:

• Perichondrium
• Chondroblasts
• Chondrocytes
• Lacunae
• Isogenous groups
• Territorial/Intraterritorial matrix
• Click here for a larger, printable image

Clinical note: The avascularity of cartilage limits its size according to the distance small molecules can diffuse through the matrix to nourish the chondrocytes. The matrix is a barrier to the entry of large proteins like immunoglobulins and also to lymphocytes, which is important for the practice of reconstructive and cosmetic surgery since cartilage can be transplanted from one individual to another without rejection by the immune system.
 

Next, let's compare hyaline cartilage to elastic and fibrocartilage.