Which is the primary structural protein of the connective tissue extracellular matrix?

Which is the primary structural protein of the connective tissue extracellular matrix?

• A. Collagen fibers
• B. Goblet cells
• C. Keratin fibers
• D. Elastin fibers

Answer: (A)

The main concept here is identifying the primary structural component that forms the connective tissue extracellular matrix. Collagen fibers fill that role, providing the main framework and tensile strength that give connective tissues their structure and resilience. Collagen is the most abundant protein in the ECM and is produced by fibroblasts, assembling into strong fibrils and fibers thanks to its triple-helix structure. This network supports tissues such as skin, bone, and tendons. Goblet cells are mucus-secreting epithelial cells, not part of the ECM protein framework. Keratin fibers are responsible for structural support in epithelial cells and hair, not the connective tissue matrix. Elastin contributes elasticity but does not form the primary structural scaffold like collagen does. So collagen fibers are the best answer.

The main concept here is identifying the primary structural component that forms the connective tissue extracellular matrix. Collagen fibers fill that role, providing the main framework and tensile strength that give connective tissues their structure and resilience. Collagen is the most abundant protein in the ECM and is produced by fibroblasts, assembling into strong fibrils and fibers thanks to its triple-helix structure. This network supports tissues such as skin, bone, and tendons.

Goblet cells are mucus-secreting epithelial cells, not part of the ECM protein framework. Keratin fibers are responsible for structural support in epithelial cells and hair, not the connective tissue matrix. Elastin contributes elasticity but does not form the primary structural scaffold like collagen does. So collagen fibers are the best answer.