biology of the skin

After being quite reckless with looking after my skin in my teens, I really started to understand just how important it is to look after, once I understood the biology of it. Once you realise what you put on your skin actually has an affect on so many crucial elements, it starts opening your eyes. Your skin may not seem like it’s being affected straight away, but the cells within are, which will eventually become evident over time. So I thought I would write a brief summary of the skin and it’s components…

 “Your skin protects your body from infection and extreme temperatures, maintains your balance of fluids and even synthesizes vitamin D for your own personal use.”

The skin is your largest organ, which is apart of the Integumentary System. This system comprises of the hair, skin, nails and exocrine glands.

There are three main layers of the skin: epidermis, dermis & hypodermis.



  • This is the skin that you can see when you look in the mirror.
  • The epidermis is made up of 5 sub-layers that work together to continually rebuild the surface of the skin - Stratum Corneum, Stratum Lucidum, Stratum Granulosum, Stratum Spinosum & Stratum Basale.
  • The Stratum Corneum is the outermost layer that protects the body from the environment (free radical damage) and bacteria and viruses that cause diseases.
  • The epidermis is made up of cells called keratinocytes, which provide the most important protein of the epidermis – keratin. They make the skin tough and provide protection from damage and stress.
  • For those areas that need greater protection like you hands and feet, the outer keratin layer of the epidermis is much thicker.
  • Keratinocytes actually stem from the base layer of the skin and work their way up to the outer layer where they eventually shed and get replaced by new cells pushed up from below. (This process is known as differentiation)
  • Scattered in the base layer of the epidermis (stratum basale) are cells called melanocytes, which produce the pigment melanin, which gives the skin its colour. Its other main job is to protect us from ultraviolet radiation from the sun, which damages DNA, which can result in skin cancer.



  • This layer below the epidermis.
  • It is mostly made up of collagen and a small amount of elastin, which gives the skin its flexibility and strength.
  • It contains blood vessels, nerve endings, hair follicles, sweat glands and sebaceous glands (oil glands).
  • The blood vessels provide nutrients to the skin while also regulating body temperature.
  • The nerve endings sense touch, pressure, pain and temperature. Some areas of the body like fingertips and toes contain more nerve endings, which make them sensitive to touch.
  • The hair follicles produce all of the different types of hair found on the body and plays a role in regulating body temperature and providing protection.
  • The sweat glands produce sweat when we’re stressed or hot. As the sweat evaporates off the body it helps to cool us down.
  • The sebaceous glands exude sebum into the hair follicle. Sebum is an oil that keeps the skin moisturised and also acts as a barrier.



  • This layer is below the dermis and consists mostly of fat cells, which keeps the skin soft and plump.
  • This layer also helps insulate the body, provides protection and stores energy.
  • The fat layer varies throughout the body, for example the layer of fat around the eyelids is about a fraction of an inch whereas the stomach would have several inches.


So they’re the main components of the skin and each layers different roles and functions. Of course there is so much more to it, but that’s for another day!

I think after knowing the many processes the skin goes through to protect and rebuild itself, I felt more inclined to work with it and pay attention to what it was saying. I now am not so harsh with it and I use products that I know will assist in its health. And my skin has never been happier!