Britannica Sources used in this answer

How do membrane-coating granules contribute to the skin barrier?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

Learn how regenerative properties of the skin helps to protect the human body from the external environment — human skin Human skin, whose cells are generated continuously by the body, serves as a protective barrier between the inside of the human body and the environment.

Membrane-coating granules, also known as lamellated bodies, play a critical role in establishing the skin's protective barrier against water loss and the inward passage of foreign chemicals.123

These granules are produced within the living epidermal cells of the spinous and granular layers. As these cells progress toward the surface, the membrane-coating granules migrate to the cell periphery and discharge their contents into the intercellular spaces.3

This process results in the spaces between the compacted, cornified cells of the lower stratum corneum being tightly packed with lipid (waxy) platelets. These lipid lamellae act as a seal, creating a functional barrier that prevents the outward loss of water and restricts the inward movement of substances.12