Cartilage is made up of a specialised connective tissue called cartilaginous tissue. In this chapter you will learn that cartilage originates from mesenchyme and can grow by apposition or intussusception, and in many cases is surrounded by a connective tissue sheath called perichondrium. You will see that the cells of the cartilage are the chondrocytes, and that the extracellular matrix consists mainly of collagen fibres (type II collagen), and large aggregates of a specific proteoglycan (aggrecan). You will study that there are different varieties of cartilage (foetal, hyaline, elastic, fibrous and articular cartilage).