Layers of the Skin - Epidermis - Dermis - Hypodermis

In biological terms, your skin is the single biggest organ in your body, and like every other organ (e.g., heart, liver, lungs, etc), skin is comprised of many different types of tissues, all doing different jobs. These tissues are then made up of various cells. There are three layers of the skin called the epidermis, dermis and hypodermis.

In simple terms, the skin acts like an umbrella, protecting your body. The skin is a barrier, keeping everything that you need to live in, and everything else out, including bacteria, rays of the sun and other harmful particles, while simultaneously taking care of the release of waste products and protecting your internal organs from injuries.

The skin is made up of a number of layers, but the deeper layers are not visible. While wrinkles and acne are common, visible skin problems, they are actually the result of what is going on deep below the top layer of the skin.

If you have ever seen a cross sectional diagram of the skin, you would know that it is made up of three main layers: the hypodermis, dermis and epidermis. What exactly does each layer of skin do?

Diagram Showing Layers of Human Skin Epidermis - Dermis - Hypodermis

Outer Layer

The epidermis is the skin layer that is visible, covering the entire body from head to toe. The epidermis is in itself made up of three separate layers, which are all comprised of millions of connecting tissues of different thickness woven together. The epidermis under your eyes is very thin, whereas it is thick on your heel.

The epidermis acts as a barrier, and because of this it takes a constant beating and is always being shed. New skin is constantly being made in the bottom layer of the epidermis to replace the top layer. The epidermis is scattered with pores and shafts that contain hairs, and also holds melanin, which is what gives your skin its color or pigmentation to protect from the UV light produced by the sun.

Middle Layer

The dermis is the hub of all operations in the skin where a lot of action takes place. The dermis is tucked away between the epidermis and hypodermis. It is the layer that holds all the blood vessels, nerves, hair follicles, collagen and sweat glands. Capillaries (tiny blood vessels) supply nutrients to the skin and the nerves give our sense of touch, while tiny muscle fibers control the raising and lowering of hairs and goose pimples. The dermis is also responsible for catching, trapping and dealing with any stray bacteria that has been able to travel through the epidermis.

Inner Layer

Temperature control is the main job of this deep layer of skin, the hypodermis. This is because fatty deposits and collagen are found here, which insulate our bodies and make sure that we stay warm. The hypodermis is also where adipose tissues are found. Adipose tissues are all the connective tissues that form this layer of skin, and the hypodermis acts like a shock absorbing mechanism to reduce impact from outside and keep us free from injury.