The skin is the body’s largest organ (weighing an average of 2.7 kilograms). Around 25% of all bodily waste exits the body via the skin. If our bodies are not functioning properly, this will quickly become evident on our skin. It is waterproof and retains its elastic quality whilst being washed repeatedly – the most astonishing and versatile organ! The entire process of replacing your skin with new cell growth takes between four to six weeks, so if you are changing your diet or skincare routine, it is going to take that long before the full effect can be noticed.
The skins three main functions:
The primary function of the skin is to act as a physical barrier to the outside world protecting us against injuries, sunlight, temperature variations, toxins and pathogens (virus, bacterium or microorganisms).
The skin regulates several aspects of physiology such as body temperature via sweat, hair and changes in peripheral circulation. It also acts as a reservoir for the synthesis of vitamin D.
The skin is the body’s largest sensory organ delivering the sense of touch. Without our skin we wouldn’t be able to feel! It has thousands of nerve endings with some parts of the body having higher concentrations than others such as your fingertips.
The three layers of our skin:
1. The Epidermis
The epidermis is the top of layer of the skin (the bit you can see). The thickness of this layer depends on your age and sex. It is thicker in different areas of our body for example the sole of your foot. The epidermis contains several layers of skin itself.
- Basal cell layer (stratum germinativum): the area in which our cells continuously divide and new skin cells are created each day. Some of these cells pass through the epidermis to the outer layer, pushing other cells upwards as they move. This layer also produces melanin which helps to protect against damage from ultraviolet light.
- Spinous cell layer (stratum spinosum): this layer is above the basal cell layer and is often referred to as the ‘prickle cell layer’. The cells that pass through this layer produce keratin, a protein found in healthy skin, hair and nails. The main function of the keratinocyte cells is to create a barrier against infections, bacteria, mould and fungi from entering the body.
- Granular layer (stratum granulosum): this is where our cells start to flatten out and lipids and more keratin are produced to waterproof the skin.
- Outer skin layer (stratum corneum): once cells reach this layer, they flatten out, shed and die being replaced by the new cells from below. This layer is exposed to ultraviolet light which influences the proportion of melanin produced within your skin. The surface of our skin is only the thickness of a single piece of paper!
2. The Dermis
This is the middle layer (and the thickest) of your skin which is connected by a membrane and made up of collagen and elastic, fibrous tissue as well as nerve endings. It contains our hair follicles, sweat and oil glands and crucial blood vessels that removes waste and carry’s essential nutrients and oxygen.
3. The Hypodermis
Also known as the subcutaneous layer, this layer is composed of a vast network of connective tissue entwined from fat cells. It stores essential nutrients to provide insulation and keeps our body temperature steady. It is responsible for providing the skin with its shapes and curves and acts as a cushion protecting the outer layer. The hair we see on our skin starts in this layer, travelling through the dermis to the outer visible layer of the epidermis. Sebum, the skins natural oil and lubricant, allows the hair to be waterproof, flexible and shiny, coating itself whilst it travels towards the outside air.