From the Guidelines
The dermis does not contribute to the skin's barrier function, as it is a layer of connective tissue that provides support and structure to the skin, rather than a physical barrier 1.
Key Components of the Skin's Barrier Function
- The stratum corneum plays a crucial role in maintaining the skin's barrier function, providing a physical barrier against water loss and external factors 1.
- Lamellar bodies (Odland bodies) also contribute to the skin's barrier function by producing lipids that help to seal the intercellular spaces 1.
- Age can impact the skin's barrier function, with factors such as UV radiation and low humidity potentially disrupting the skin's natural barrier, although it is not a direct component of the barrier function itself 1. The dermis, on the other hand, is composed of connective tissue that provides support and structure to the skin, but does not directly contribute to the skin's barrier function 1.
From the Research
Skin Barrier Function
The skin's barrier function is a complex process that involves multiple components, including:
- Stratum corneum: the outermost layer of the epidermis, responsible for preventing water loss and protecting against external factors 2, 3, 4
- Lipids: synthesized in keratinocytes and extruded into the extracellular domains, forming a lipid-enriched barrier 2, 5
- Corneocytes: protein-enriched cells that provide a physical barrier 2
- Lamellar bodies (Odland bodies): involved in the formation of the lipid barrier 5
Components that Contribute to Skin Barrier Function
The following components contribute to the skin's barrier function:
- Stratum corneum: provides a physical barrier against external factors 2, 3, 4
- Lamellar bodies (Odland bodies): involved in the formation of the lipid barrier 5
- Dermis: although not directly involved in the barrier function, the dermis provides a supportive structure for the epidermis 6
Component that Does Not Contribute to Skin Barrier Function
Based on the available evidence, age is a factor that affects the skin's barrier function, but it is not a component that contributes to the barrier function itself. Instead, age-related changes can disrupt the skin's barrier function, leading to increased susceptibility to skin disorders 6. Therefore, age is the component that does not contribute to the skin's barrier function.