What occurs when tissue loading surpasses the yield point?

• A. Elastic deformation
• B. Plastic deformation
• C. Creep
• D. Fracture

Answer: (B)

Surpassing the yield point moves the tissue from elastic to plastic deformation. Up to the yield point, stretching is reversible—the tissue returns to its original shape when the load is removed. Beyond yield, the deformation becomes permanent because the internal structure—like collagen fibers—slips, reorients, and sustains micro-damage that cannot fully recover. Creep describes time-dependent deformation under a sustained load and isn’t the immediate consequence of crossing the yield point, while fracture is a potential later failure after extensive damage but not the direct result of just exceeding yield.