Skin XXXXXXXXXXXXXXXXXX Flashcards
Skin as an organ
- Combination of the 4 primary tissues: epithelium, connective tissue, muscle, nerve.
- Epidermal cells are termed keratinocytes
- Largest organ in the body
- Own nerve and blood supply
- One of the first organs noticeable in patients
- Has its own pathological conditions:
eg. sunburn, acne, eczema, psoriasis, melanoma
•Provides important external evidence of underlying systemic conditions: eg. liver disease, systemic sclerosis, mitral stenosis, urticaria
Skin structure
2 layers which differ in function, embryological origin, appearance
1.Epidermis
- Epithelium
- Forms boundary between internal and external compartments
2.Dermis
- Connective tissue
- Gives structural strength
(Hypodermis: Adipose (fatty) CT layer beneath skin = superficial fascia or subcutaneous tissue, anchors skin to underlying structures - not part of skin)

Epidermis
- Outer layer of skin
- Epithelial = Stratified squamous keratinising epithelium
- Ectodermal origin

4 Epidermal cell types
Keratinocytes:
– Most frequent, contain keratin (contains sulphur), hard,
resistance to abrasion.
– Extrude lipids – waterproofing.
– Constantly dividing – self regeneration protecting from
trauma and other damage.
Melanocytes: pigment formation
-
Langerhans cells: immune surveillance
Merkel cells: touch receptors
