Both are constituent parts of the skin, however, there are clear differences between the dermis and epidermis. The dermis is a layer of skin located under the epidermis and firmly connected to it at the bottom while the epidermis is the outer layer of the skin, which is in contact with the environment.
Differences between dermis and epidermis:
- The dermis is an inner layer of skin 30 times thicker than the epidermis.
- The epidermis is the outer layer of the skin with a thickness of up to 0.1 mm on the eyelids.
- The dermis has blood vessels.
- The epidermis lacks blood supply.
- The epidermis has 4 or 6 layers.
- The dermis has two layers.
Dermis
It is the layer of skin that is located under the epidermis and is firmly connected to it by the inner surface of the basement membrane.
Functions of Dermis
Its function is protective, it is the second line of defense against trauma as it is up to 30 times thicker than the epidermis.
The deeper layers of the dermis contain hair follicles with arrector pili muscles and sebaceous glands.
Another function of the dermis is to nourish the epidermis since it has blood vessels while the epidermis does not. It has a thermoregulatory function, it contracts if it is cold and expands if it is hot, it has sweat glands.
It is what offers support to the epidermis thanks to the dermal papillae and the collagen fibers it contains.
It is formed by the papillary layer or upper dermis and the reticular layer or deep dermis.
Epidermis
It is the outer layer of the skin and represents the body’s most important barrier to the environment. It is up to 1.5 mm thick on the palms of the hands and soles of the feet and 0.1 mm on the eyelids.
Functions of Epidermis
The epidermis lacks blood supply and is nourished through diffusion from the dermis. It has keratinocytes, Langerhans cells, melanocytes, Merkel cells and inflammatory cells.
The epidermis has 4 or 6 layers depending on the region of the skin, the outermost layer is known as the stratum corneum, followed by the translucent layer, granular layer, spinous layer and the basal layer.
Its function is to protect against the growth of bacteria and fungi and UV rays.
