Skin Structure & Function

structure and function

The skin is an organ that provides the outer protective wrapping for all the body parts. It is the largest organ in the body. It is a waterproof, airtight and flexible barrier between the environment and internal organs. It keeps the internal environment of our body stable. The skin is divided into 3 layers, the epidermis, the dermis and the subcutaneous layer.

Epidermis

The epidermis is the outer layer of the skin. It is a mosaic of cells glued together and its thickness depends on the location on the body. On the palms and soles the epidermis is thick, flexible and resists mechanical injury. On the eyelids it is very thin and allows maximum movement. The epidermis prevents loss of water and body fluids, resists mechanical and chemical injury and protects against bacteria, viruses and parasite infections.

There are 3 main groups of cells in the epidermis

The skin is the largest organ of our body. Its main function is to act as a barrier against environmental adverse effects. Skin aging is the result of several factors, such as:

• Keratinocytes (skin cells)
• Melanocytes (pigment cells)
• Langerhans cells (immune cells).

The main cell in the epidermis is the keratinocyte, which develops from the bottom or basal layer and then migrates upwards over a period of about four weeks to the outer surface (stratum corneum) where it is shed. Langerhans cells are specialised immune cells that are an important part of the body’s immune response to foreign materials and infections.