Which protein fiber in the dermis contributes to skin flexibility and firmness?

Elastin is the protein fiber in the dermis that plays a crucial role in contributing to the skin's flexibility and firmness. It allows the skin to stretch and recoil, ensuring that it can withstand the various movements and stresses placed upon it. This property is essential for maintaining skin elasticity, which helps prevent sagging and contributes to a youthful appearance. As people age, the production of elastin decreases, leading to a loss of firmness and increased visibility of fine lines and wrinkles.

In contrast, while collagen is also important for skin structure and strength, it primarily provides support and firmness rather than flexibility. Keratin is a protein that serves a protective role primarily in the outer layer of skin, hair, and nails. Reticulin, often found in the dermal matrix, supports the structure but does not have the same flexibility properties as elastin. Thus, elastin is specifically characterized by its ability to maintain the skin’s resilience and pliability.