Main Model
Lateral : Papillary 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.