As you might have heard, the largest organ in a human body is the skin. The average adult carries around about 8 pounds of skin covering 22 square feet. But far from being a simple way of covering up one’s insides, skin is actually a very complex multi-layered thing which performs a variety of important tasks. OROGOLD Cosmetics helps you to get to know your skin.

The outer layer is called the epidermis, and it’s the main line of defense against injury, bacteria, ultraviolet radiation and anything else the world throws at you. To this end it’s incredibly strong for something so thin, and heals remarkably quickly compared to other body parts. It also has to act as a gatekeeper, by letting certain things in and out, while blocking others. It manages this by being acidic enough to dispose of most pathogens and tight enough that only the smallest particles can pass through.

The main thing that needs to get through the epidermis is water. In order to maintain body temperature, there’s always a bit of water evaporating off you. Sweating is just the same thing in overdrive. Skin damage like sunburn, or the natural effects of aging, disrupt this process and can lead to dry skin through increased water loss. This in turn makes the epidermis weaker, less flexible and worse at protecting the body. As such, moisturisers are important far beyond simple cosmetic purposes, particularly as you get older.

Underneath the epidermis lies a thin layer called, for obvious reasons, the basement membrane. This has two simple yet vital functions. Firstly, it’s the next line of defence. If anything makes it past the epidermis when it shouldn’t, the basement membrane stops it from getting any deeper and doing real damage. Secondly, it firmly ties together the epidermis with the third layer, the dermis.

The dermis is the busiest part of the skin. It’s the cushiony part that stops you from getting bruised too easily and holds the connective tissue that give skin its flexibility. It’s also got all the nerve cells that let you feel touch, pain, temperature and the like, as well as sweat glands, blood vessels and hair follicles. In short, it’s the real skin, while the other two layers are just there to make sure it can do its job properly.

This multi-layered structure is why skincare products are so complex. To have any real effect, they need to deliver active ingredients past the epidermis and basement membrane, all the way to the dermis. That’s also why dermatologists are so excited about nano-particle developments – it represents the best and safest way to accomplish that. Although it’s only a few millimetres at most, skin-deep turns out to be very deep indeed.