Main Model
Lateral : Reticular layer of dermis
Dermis
The dermis is formed by two layers without distinct boundaries:
1. The papillary layer, consisting of numerous dermal papillae split by interpapillary pegs, form the dermal-epidermal junction.
The junctional interface is stabilized by hemidesmosomes anchoring basal keratinocyte cells to the basal lamina. Loose connective tissue (fibroblasts, collagen fibers, and thin elastic fibers) provides mechanical anchorage and nutrients to the overlying epidermis.
2. The reticular layer, containing thick bundles of collagen fibers and coarse elastic fibers.
Hemidesmosomes on the basal domain of keratinocytes of the stratum basale attach the epidermis to the basement membrane and the papillary layer of the dermis by a plate/plaque-anchoring filament complex. The molecular and structural components of the hemidesmosome are of considerable importance for understanding the cause of blistering diseases of the skin.
Hair follicles and sweat and sebaceous glands are epidermal derivatives present at various levels of the dermis.