Mature cartilage cells that reside in lacunae; a cell which has secreted the matrix of cartilage and become embedded in it.

• A. Osteocytes
• B. Adipocytes
• C. Fibroblasts
• D. Chondrocytes

Answer: (D)

Chondrocytes are mature cartilage cells that reside in lacunae within the cartilage matrix. They originate from chondroblasts, which secrete the extracellular matrix of cartilage and, as the matrix accumulates, become embedded in it and differentiate into chondrocytes. Once inside their lacuna, these cells maintain and remodel the cartilage, sustaining its resilient, flexible nature. This set of features distinguishes them from other cell types like osteocytes (bone cells in bone matrix), adipocytes (fat cells), or fibroblasts (cells that produce fibers in connective tissue but are not specific to cartilage). The lacunae and the cartilaginous matrix together define how these cells function in cartilage.