Light microscopy of a growth plate in a growing bone. The growth plate is located towards the end of the bone at the epiphysis. It is formed of cartilage consisting of proliferating cartilage cells (chondrocytes) and the matrix which they produce (blue). Mature chondrocytes enlarge significantly before undergoing cell death but their cartilage matrix persists and acts as a surface upon which bone-forming cells (osteoblasts) deposit bone matrix (pink) in the lower half of the image. Over time the bone slowly grows in length until the growth plate stops making cartilage. Magnification x240 when narrow width printed at 10 cm.