What is cartilage tissue made of?

Cartilage tissue is composed of specialized cells and a complex extracellular matrix. This matrix gives cartilage its unique properties.

Components of Cartilage Tissue

Cartilage is not a uniform substance; rather, it's a composite material crafted by specialized cells. The primary components are:

Chondrocytes: These are the specialized cells responsible for producing and maintaining the extracellular matrix. They reside within lacunae, small cavities within the matrix.
Extracellular Matrix: This is the main structural component and is secreted by chondrocytes. It consists of:
- Collagen Fibers: Provide tensile strength, resisting pulling forces.
- Elastin Fibers: Provide elasticity, allowing cartilage to deform and return to its original shape.
- Ground Substance: A gel-like substance composed of proteoglycans (proteins with attached glycosaminoglycans, or GAGs) and water. The GAGs are negatively charged, attracting water and contributing to cartilage's resilience and ability to withstand compression.

The specific composition of the extracellular matrix varies depending on the type of cartilage, influencing its properties.

Component	Function
Chondrocytes	Produce and maintain the extracellular matrix.
Collagen Fibers	Provide tensile strength and resistance to pulling forces.
Elastin Fibers	Provide elasticity, enabling the cartilage to deform and return to its original shape.
Ground Substance	Provides resistance to compression due to the water held by the negatively charged GAGs. Also, allows for the diffusion of nutrients and waste products to and from the chondrocytes.

Hyaline Cartilage: Found in joints, the nose, and ribs, it's characterized by abundant collagen and provides smooth surfaces for movement.
Elastic Cartilage: Found in the ear and epiglottis, it contains many elastin fibers, giving it flexibility.
Fibrocartilage: Found in intervertebral discs and menisci, it has a high collagen content, providing strong support.