Skin

Skin facts l Skin types Skin layers l  Skin aging

Skin facts 

  • Skin’s biggest job is protection. It’s a tough, elastic, flexible and waterproof covering and maintains the body’s correct temperature.
  • Skin is the largest and one of the hardest working organs in the body.
  • Skin covers and average area of about 1.8 metres on an adult and makes up 1/6 of your body weight.
  • Skin continually renews itself. Old skin cells are gradually shed and replaced by new ones every 28 days.
  • Skin cells grow and and renew faster than any other organ.
  • You have 19 million skin cells in every square inch of your body.

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Skin types

The Fitzpatrick skin type scale is an international skin type classification, which identifies differences in skin type and sensitivity to sunburn.

Skin has been typed into six basic categories:

Type 1: Always burning, never tan; sensitive to exposure; redheaded, freckles, Celtic background.

Type 2: Burns easily, tans minimally; fair-skinned, blue, green or gray eyes, Caucasians.

Type 3: Burns moderately, tans gradually to light brown; average Caucasian skin.

Type 4: Burns minimally, always tans well to moderately brown; olive skin.

Type 5: Rarely burns, tans profusely to dark; brown skin.

Type 6: Rarely burns, least sensitive; deeply pigmented skin.

 Skin types

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Skin layers

Skin is made up of three layers.

  1. Epidermis - the outer layer. It’s about 20 cells deep - about as thick as a sheet of paper. The top part of the epidermis is composed of dead cells which are constantly shed. Underneath the dead cells are live squamous cells, and under these are basal cells which are constantly reproducing. Cells called melanocytes are found in the epidermis. These cells produce a brown-black skin pigment called melanin, a pigment that helps screen against the harmful effects of ultraviolet radiation (UVR).
  2. Dermis - below the epidermis. This layer contains tiny blood and lymph vessels.
  3. Subcutaneous layer - below the dermis. This is mainly fat.

 Skin anatomy

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Skin aging

Over 80% of skin aging is caused by exposure to UVR. Skin aging is also caused by genetic factors and  factors such as unhealthy diet, sleeping on your stomach and gravity.