Understanding The Skin & It's Many Layers
There are three main layers of skin that offer all of these amazing protections and more.
The epidermis is the water-resistant outer layer of skin and the body’s first line of defence against environmental elements, ultraviolet radiation, bacteria, and other germs. It’s made up of 4-5 sublayers of closely packed cells. The epidermis is responsible for the cell renewal cycle: dead skin cells slough off the stratum corneum (the superficial sublayer of skin visible to the eye) and are replaced with new, healthy cells that generate within deeper sublayers of the epidermis. The epidermis also includes your pores, which allow oil and dirt to escape your body.
The epidermis contains several specialized cells, including:
- Keratinocyte cells that create and store keratin, the protein that strengthens skin
- Langerhans cells that help prevent infection and protect the immune system
- Melanocyte cells that produce melanin, the pigment that determines skin colour.
- Squamous cells and basal cells, which can mutate and cause basal cell carcinoma and squamous cell carcinoma.
The dermis is the layer of skin under the epidermis. This layer of skin contains connective tissues and houses your body’s hair follicles, sweat and oil glands, and blood vessels. The dermis also contain nerve endings that are responsible for sending messages to the brain when you burn your hand on a hot stove or feel an itch at the back of your neck. Blood vessels located in the dermis help supply your skin with fresh blood carrying the oxygen and nutrients it needs to be healthy.
Within its connective tissues, the dermis produces two important proteins:
- Collagen and elastin, which are responsible for the shape, structure, firmness, and elasticity of your skin.
The hypodermis is made of subcutaneous (under the skin) fats, connective tissues, blood vessels, and nerve cells. It’s the layer of skin where fat is deposited and stored. The blood vessels in the hypodermis are bigger and connect to the rest of your body. Stored fat helps regulate body tissue and cushion your body’s internal organs against bumps, hard impact, and falls.
The tissue in the hypodermis produces one important cell:
- Adipocytes that store fat used for energy, cushioning, and insulation.