Cartilage is a firm yet flexible type of connective tissue found in several places throughout the body, including joints, the rib cage, the ears, the nose, and the airways. Unlike bone, it has no blood supply of its own, which shapes both how it functions and how it heals.
A Smooth, Cushioning Surface
One of cartilage's most important roles is found at joints, where a smooth layer called articular cartilage covers the ends of bones. This layer provides a low-friction surface that allows bones to glide smoothly against one another during movement, while also acting as a cushion that helps absorb and distribute the forces placed on a joint.
Providing Flexible Structural Support
In places like the ears, the nose, and parts of the airway, cartilage provides structural support while still allowing a degree of flexibility that rigid bone wouldn't offer. This is why the external ear and the tip of the nose can bend and flex without breaking, unlike bone elsewhere in the body.
A Template for Bone Growth
Cartilage also plays a temporary but essential role during growth. In children and adolescents, growth plates made of cartilage are found near the ends of long bones, and these plates gradually convert into bone as growth continues, a process that determines how bones lengthen over the course of childhood and adolescence until growth is complete.
Limited Capacity for Repair
Because cartilage lacks its own direct blood supply, receiving nutrients instead through a slower diffusion process from surrounding fluid, it generally has a more limited capacity to repair itself compared to tissues with a direct blood supply, such as bone or muscle.
Background
Cartilage has been recognized as a distinct tissue type since early anatomical study, but a detailed understanding of its unique structure and its lack of direct blood supply developed further through microscopic and biochemical research over the 19th and 20th centuries. This research helped explain both cartilage's valuable cushioning properties and its comparatively limited ability to heal once damaged.