How does the skin hold body fluids without leaking them?
Epidermis, the topmost layer of human skin is responsible for holding all body fluids inside. Among the numerous layers of epidermis is the 'stratum granulosum', configured in a three-dimensional checkerboard pattern with 14 sides, which makes the skin leakproof. Further, the cells in this region produce a glue, which binds this shape together, so that the skin doesn't fall apart.