During remodeling, how does collagen change to increase tissue strength?

During remodeling, how does collagen change to increase tissue strength?

• A. Type III collagen is replaced by Type I collagen
• B. Type I collagen is replaced by Type III collagen
• C. Collagen becomes less organized and weaker
• D. Collagen is not involved in remodeling

Answer: (A)

During remodeling, tissue strength grows as the initial, more elastic collagen is systematically replaced with stronger, thicker fibers. Specifically, collagen type III that is laid down early in healing is gradually replaced by collagen type I. Type I collagen forms densely packed, highly cross-linked fibrils that resist tensile forces, so this transition increases the tissue’s tensile strength and stiffness. Enzymatic cross-linking and realignment along the direction of mechanical load further enhance this strength as the tissue matures. The other scenarios don’t fit the remodeling goal: replacing type I with type III would reduce strength, collagen becoming less organized and weaker contradicts the goal of maturation, and collagen is indeed central to remodeling.

During remodeling, tissue strength grows as the initial, more elastic collagen is systematically replaced with stronger, thicker fibers. Specifically, collagen type III that is laid down early in healing is gradually replaced by collagen type I. Type I collagen forms densely packed, highly cross-linked fibrils that resist tensile forces, so this transition increases the tissue’s tensile strength and stiffness. Enzymatic cross-linking and realignment along the direction of mechanical load further enhance this strength as the tissue matures.

The other scenarios don’t fit the remodeling goal: replacing type I with type III would reduce strength, collagen becoming less organized and weaker contradicts the goal of maturation, and collagen is indeed central to remodeling.