Which protein found in the dermis contributes to skin firmness?

• A. Elastin
• B. Collagen
• C. Keratin
• D. Fibroblasts

Answer: (B)

Collagen is the primary protein found in the dermis that contributes significantly to skin firmness and structural integrity. It is the most abundant protein in the human body and forms a scaffold that provides strength and support to the skin. Collagen fibers are long and strong, allowing the skin to resist stretching and maintain its shape over time.

While elastin, another protein found in the dermis, provides elasticity and allows the skin to return to its original shape after being stretched, it does not contribute as directly to firmness as collagen. Keratin, on the other hand, is primarily found in the epidermis and plays a key role in protecting the skin but is not involved in the structural firmness of the lower layers. Fibroblasts are cells that produce collagen and elastin but are not proteins themselves. They are essential for the maintenance and repair of skin but do not directly contribute to skin firmness.

Thus, collagen stands out as the key protein responsible for maintaining the firmness of the skin in the dermal layer.