Periderm week 24

As differentiation of the underlying epidermal cell layers approaches completion, the periderm is sloughed into the amniotic fluid. Some desquamated periderm cells accumulate on the skin surface. By week 24 the periderm is gone.

Note the complex multi-layered stratified and differentiated epidermis. The 'basket weave' pattern of darkly staining material above the nucleated cells is the first appearance of a comified cell layer in interfollecular epidermis. The periderm has completely regressed.

To understand what has been transpiring underneath the periderm, and why it is no longer needed, select stratification from the main index.