Elastic cartilage. Coloured scanning electron micrograph (SEM) of a section through elastic cartilage (green) from a pinna (external ear). Elastic cartilage, which maintains the shape of the pinna, contains fibres of the protein elastin (not seen). Cartilage is a firm, flexible connective tissue composed of chondrocyte cells embedded in holes (black) in an extracellular matrix. The skin (grey/pink) surrounding the cartilage is also seen. The pinna channels sound waves into the internal ear. Magnification unknown.