The dermis is the layer of the skin lying between the epidermis and subcutaneous fat.
It is mainly responsible for the strength of the skin.
It also feeds the epidermis as blood vessels are present.
It also contains nerves and plays a crucial role in the regulation of body temperature.
It is divided in reticular dermis and papillary dermis.
The difference is mainly in the density of components and the papillary dermis is in close contact with the epidermis.
Dermal papillae are projections of the dermis into the epidermis: they contain blood vessels and are in close contact which the epidermal stem cells located in the basal layer.
The dermis is primarily affected in conditions such as Scleroderma and Granuloma Annulare and is involved in the inflammatory components of Psoriasis and Eczema.