Skin - The difference between the epidermis and the dermis
In terms of surface area, the skin is one of the largest organs in the human body, with a surface area of approximately 2 square metres. It is almost one sixth of the total body weight and has several vital functions including:
- Providing a protective barrier.
- Reducing harmful effects of UV radiation.
- Acting as a sensory organ (touch, detects temperature).
- Preventing loss of moisture.
- Helping to regulate temperature.
- Production of vitamin D.
Human skin is made up of several layers. The two main layers however, are the epidermis and the dermis.
What is the epidermis?
The epidermis is the outer layer of the skin. It has elasticity and is continually being regenerated. The thickness varies on different parts of the body, but it is between 0.5 and 4mm thick, and made up of cells called keratinocytes, corneocytes and melanocytes.
The function of the epidermis is to provide a physical barrier between the body and the environment and to repel moisture. It also prevents excessive water loss.
What is the dermis?
The dermis is the inner layer of the skin, and includes: hair follicles, nerves, sweat glands, small blood vessels and sebaceous glands. It is made up of connective tissue and consists of two layers, the stratum papillare (upper layer) and the stratum reticulare.
The dermis acts as a supporting structure for the epidermis and contains proteins such as collagen and elastin. These provide the skin with strength, the ability to stretch and the ability to return to its original shape. In older people, these proteins start to decrease, making their skin more delicate.
Protecting the skin of care home residents
For care home staff, maintaining healthy skin for residents is essential. Their skin may be fragile and may come into frequent and prolonged contact with fluids, for example: urine, faeces or fluids from wounds. This can cause over-hydration of the skin, which can result in damage such as maceration (softening of tissue that has remained moist) and excoriation (worn away or rubbed). If the skin is damaged, it is more susceptible to infection. It is therefore very important to use products that create a barrier on the skin to help keep it healthy and free from the risk of infection.
For more information on skin care products for care home residents, please call: 0845 226 0185 and ask for Kerry or Jenny.
This blog item is based on sections of an article by an Independent Tissue Viability Nurse published in ‘Nursing and Residential Care’ magazine April 2012 and information from the HSE website.
E-mail us to request information on skin care for care home residents.