Membrane around the cartilage.

• A. Perichondrium
• B. Epiphyseal plate
• C. Lateral condyle of femur
• D. Facet for plantar calcaneonavicular ligament

Answer: (A)

The membrane around cartilage is the perichondrium. It’s a dense connective tissue covering most cartilage, with an outer fibrous layer that protects and contains vessels and nerves, and an inner chondrogenic layer that can give rise to new cartilage cells (chondroblasts) for growth and repair. This layer supplies nutrients to the avascular cartilage by diffusion and is especially important for appositional growth, where new cartilage is added at the surface. Articular cartilage, in contrast, lacks a perichondrium at the joint surfaces, which is why the surface is smooth and lubricated by synovial fluid rather than by perichondrial growth. The other options aren’t membranes around cartilage: the epiphyseal plate is a growth region in long bones, the lateral condyle of the femur is a bone landmark, and the facet for the plantar calcaneonavicular ligament is a joint surface feature, not a surrounding membrane.