Skin XXXXXXXXXXXXXXXXXX

Question 1

Skin as an organ

Answer 1

• 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

Question 2

Skin structure

Answer 2

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)

Question 3

Epidermis

Answer 3

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

Question 4

4 Epidermal cell types

Answer 4

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

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Langerhans cells: immune surveillance

Merkel cells: touch receptors