Question

As their aspect ratio is high, collagen fibers are not effective under:

• A. Axial tension
• B. Transverse tension
• C. Transverse compression
• D. Axial compression

Hint:

The String Analogy for Collagen: Collagen fibers act like structural pieces of string: - They handle axial tension beautifully (pulling a string taut supports a load). - They collapse instantly under axial compression (pushing the ends of a string together causes immediate structural buckling).

Answer 1

The Correct Option is D

Concept: Collagen is the primary structural protein found within extracellular matrices across human connective tissues (such as tendons, ligaments, and skin). Mechanically, collagen exhibits a high aspect ratio, meaning its longitudinal length is orders of magnitude greater than its cross-sectional diameter. This slender, thread-like structure makes collagen behave mechanically like a rope, cable, or piece of string.

Step 1: Evaluating rope mechanics under tension.
When you pull a rope from both ends (axial tension), it becomes taut and can support very high tensile forces along its length. Similarly, collagen fibers possess immense tensile strength along their longitudinal axis, which lets them support structural loads in tendons and ligaments during movement.

Step 2: Evaluating rope mechanics under compression.
If you push the two ends of a rope or long thread together (axial compression), it cannot support the structural load. Instead, the high aspect ratio structure buckles instantly, collapsing outward with zero compressive resistance. Because collagen fibers buckle easily when subjected to longitudinal crushing forces, they provide virtually no mechanical resistance against axial compression. To handle compressive loads, the body must embed these collagen fibers within a dense ground substance matrix rich in water-retaining proteoglycans and glycosaminoglycans (as seen in articular cartilage). This makes Option (D) the correct answer.