Interstitial bone growth increases the length of long bones and requires the presence of what?

Interstitial bone growth increases the length of long bones and requires the presence of what?

• A. Epiphyseal plates
• B. Periosteum
• C. Endosteum
• D. Articular cartilage

Answer: (A)

Longitudinal growth of long bones happens at the epiphyseal growth plate, a cartilage-rich region between the end (epiphysis) and the shaft (diaphysis). In this area, chondrocytes continuously divide and create new cartilage, which is gradually ossified in a process called endochondral ossification. This cartilage-to-bone replacement pushes the two ends of the bone farther apart, lengthening the bone. Because of this, the presence of epiphyseal plates is required for growth in length. Once growth finishes, these plates ossify and form an epiphyseal line, and lengthwise growth stops. Other structures—periosteum adds bone to the outside to thicken the bone (appositional growth), endosteum lines inner surfaces and participates in remodeling, and articular cartilage covers joint surfaces but does not contribute to bone length.

Longitudinal growth of long bones happens at the epiphyseal growth plate, a cartilage-rich region between the end (epiphysis) and the shaft (diaphysis). In this area, chondrocytes continuously divide and create new cartilage, which is gradually ossified in a process called endochondral ossification. This cartilage-to-bone replacement pushes the two ends of the bone farther apart, lengthening the bone. Because of this, the presence of epiphyseal plates is required for growth in length. Once growth finishes, these plates ossify and form an epiphyseal line, and lengthwise growth stops. Other structures—periosteum adds bone to the outside to thicken the bone (appositional growth), endosteum lines inner surfaces and participates in remodeling, and articular cartilage covers joint surfaces but does not contribute to bone length.