Sampling of human<unk>  using a tape-stripping method The<unk>  (Latin for 'horny layer') is the outermost layer of the epidermis. The human<unk>  comprises several levels of flattened corneocytes that are divided into two layers: the<unk>  disjunctum and<unk>  compactum. The skin's protective acid mantle and lipid barrier sit on top of the<unk>  disjunctum. The<unk>  disjunctum is the uppermost and loosest layer of skin. The<unk>  compactum is the comparatively deeper, more compacted and more cohesive part of the<unk> . The corneocytes of the<unk>  disjunctum are larger, more rigid and more hydrophobic than that of the<unk>  compactum. The<unk>  is the dead tissue that performs protective and adaptive physiological functions including mechanical shear, impact resistance, water flux and hydration regulation, microbial proliferation and invasion regulation, initiation of inflammation through cytokine activation and dendritic cell activity, and selective permeability to exclude toxins, irritants, and allergens. This layer is composed of 15–20 layers of flattened cells with no nuclei and cell organelles. Their cytoplasm shows filamentous keratin. These corneocytes are embedded in a lipid matrix composed of ceramides, cholesterol, and fatty acids. The<unk>  functions to form a barrier to protect underlying tissue from infection, dehydration, chemicals and mechanical stress. Desquamation, the process of cell shedding from the surface of the<unk> , balances proliferating keratinocytes that form in the<unk>  basale. These cells migrate through the epidermis towards the surface in a journey that takes approximately fourteen days.
Stratum corneum
Stratum granulosum
Stratum lucidum
Neuromatrix
Episcleral layer
Inserm
Dermoepidermal junction
Stratum spinosum