Which zone of the growth plate shows actively dividing chondrocytes aligned in columns?

Which zone of the growth plate shows actively dividing chondrocytes aligned in columns?

• A. Proliferation zone
• B. Resting (reserve) zone
• C. Hypertrophy zone
• D. Calcification zone

Answer: (A)

In the growth plate, the zone where chondrocytes divide rapidly and align in columns is the proliferation zone. Here, chondrocytes undergo mitosis and stack in orderly columns parallel to the bone’s long axis, which pushes the bone ends apart and drives length growth. The resting zone holds reserve chondrocytes that are relatively inactive. The hypertrophy zone features chondrocytes that enlarge, contributing to matrix expansion and preparation for calcification. The calcification zone marks where the cartilage matrix becomes calcified and chondrocytes die, allowing invasion by bone-forming cells.

In the growth plate, the zone where chondrocytes divide rapidly and align in columns is the proliferation zone. Here, chondrocytes undergo mitosis and stack in orderly columns parallel to the bone’s long axis, which pushes the bone ends apart and drives length growth. The resting zone holds reserve chondrocytes that are relatively inactive. The hypertrophy zone features chondrocytes that enlarge, contributing to matrix expansion and preparation for calcification. The calcification zone marks where the cartilage matrix becomes calcified and chondrocytes die, allowing invasion by bone-forming cells.