The outermost layer of skin, the stratum corneum, absorbs water, although its ability to absorb liquid water versus water vapor varies depending on its condition. Untreated stratum corneum readily absorbs both liquid water and water vapor. However, when extracted, it becomes repellent to liquid water but still absorbs water vapor.
How the Stratum Corneum Absorbs Water
The stratum corneum's ability to absorb water is crucial for skin hydration and overall health. When exposed to water, the cells of this outer layer swell, leading to the characteristic wrinkling of fingers and toes after prolonged submersion in water. This absorption process is facilitated by the water content within the stratum corneum itself. Moisturizers often utilize humectants to attract and retain water within this layer, improving skin softness and suppleness. Conversely, factors impacting the stratum corneum's water content can affect its ability to absorb water.
- Liquid Water Absorption: The untreated stratum corneum efficiently absorbs liquid water.
- Water Vapor Absorption: Both treated and untreated stratum corneum absorbs water vapor.
- Skin Hydration: Water absorption by the stratum corneum is vital for maintaining skin hydration.
This absorption isn't limited to just water; the stratum corneum also plays a role in absorbing other substances, although the rate of absorption depends on various factors including the specific substance and the condition of the stratum corneum itself. The subcutaneous layer, while deeper, is also involved in absorption, particularly of injected substances.
The provided references support these observations: One reference notes the stratum corneum's absorption of liquid water and water vapor in its untreated state. Another source highlights that skin absorbs moisture, causing the cells of the outer skin layer to swell. Several sources refer to the stratum corneum's water content and its importance in skin health and absorption.
