What is the term for growth in length of bones?

What is the term for growth in length of bones?

• A. Interstitial growth
• B. Appositional growth
• C. Endochondral ossification
• D. Immobilization

Answer: (A)

Growth in length of long bones is driven by expansion within the cartilage at the growth plates, a process called interstitial growth. In this type of growth, chondrocytes divide and secrete matrix from within the cartilage, pushing the ends of the bone apart and increasing length. Later, that cartilage is gradually replaced by bone through endochondral ossification, which is the overall mechanism that forms the long bone as it lengthens. Appositional growth, in contrast, adds bone thickness rather than length, and immobilization would halt growth. So the term for lengthwise growth is interstitial growth.

Growth in length of long bones is driven by expansion within the cartilage at the growth plates, a process called interstitial growth. In this type of growth, chondrocytes divide and secrete matrix from within the cartilage, pushing the ends of the bone apart and increasing length. Later, that cartilage is gradually replaced by bone through endochondral ossification, which is the overall mechanism that forms the long bone as it lengthens. Appositional growth, in contrast, adds bone thickness rather than length, and immobilization would halt growth. So the term for lengthwise growth is interstitial growth.