Skin colour and its reaction to light melanocyte and their role in colouring the skin
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Skin Colour and its reaction to light Melanocyte and their role in colouring the skin . Skin Biology Lesson 4 . By the end of the lesson the learner should be able to . Human Colour Pigments . 4 m a i n pigments Carotenoids Deoxygenated haemoglobin Oxygenated haemoglobin

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Skin colour and its reaction to light melanocyte and their role in colouring the skin

Skin Colour and its reaction to lightMelanocyte and their role in colouring the skin

Skin Biology Lesson 4



Human colour pigments
Human Colour Pigments

4 mainpigments

  • Carotenoids

  • Deoxygenated haemoglobin

  • Oxygenated haemoglobin

  • Melanin ( melas – black)



Dendrites and their journey
Dendrites and their journey

  • Dendrites have tiny pods like threads called melanosomes ( tiny organelle – organs )

  • Membrane bound in pods contain melanin

  • Vary in size depending on race

  • Comprise 5-10% total cell in basal layer

  • Transfer melanin to the Keratinocytes



Continuing the journey
Continuing the Journey

  • Melanin is colourless when formed – once matured moves along the dendrites

  • Occurs in the stratum spinosum moves through to neighbouring Keratinocytes

  • Triggered under the influence of the sun - UV light

  • Hovers over nucleus

  • Journeys + flakes off



Melanin chemical composition
MELANIN chemical composition

Tyrosine(amino acid)

Tyronaise (enzyme)

L dopaDopa quinine converts to Eumelanin

Brown / Black Pigment

Cysteine converts to Pheomelanin

Red and Yellow Pigment


Skin colour is due to
Skin colour is due to

  • Not the quantity but the level of activity and size

  • Genetically coded


Fitzpatrick system developed by professor thomas fiztpatrick

recorded response time to sunlight

Fitzpatrick system Developed by Professor Thomas Fiztpatrick

Skin types which

Type 1 - always burn never tan

Type 2 - Usually burns but will

tan with difficulty

Type 3 -sometime burn but

will tan

Type 4 - rarely burns

Type 5 - almost never burns


Calculations of burn times
Calculations of burn times

SPF factors

How long can you stay in the

sun without burning?

Sun protection factors

15+

30+

SPF rating x by 15

Spf2 x15 = 30 mins

Spf15 x 15 = 225mins (3 hrs 45mins)

Spf30 x 15 = 450 mins (7hrs 30 mins)




Skins reaction to light
Skins reaction to light

  • Primary response

  • Is to go red and burn

  • Secondary response

  • Occurs after a few days

  • Resulting in a tan


Body responses

Level of coverage

Body responses

Depending on time and amount of sun exposure

UVB –epidermis

UVC - dermis






Disorders of the melanocyte
Disorders of the melanocyte

  • Melasma- also known as chloasmaHyper pigmentation

  • Caused by Pregnancy,

  • contraceptive pill,

  • certain drugs & stress.

  • Exposure to the sun will

  • increase melanisation

  • Once activated very

  • difficult to remove

  • Laser treatments have

  • shown good results

Vitiligo –

Hypo pigmentation.

  • The affected skin shows no melanocytes.

  • No treatment, only cosmetics

  • Michael Jackson is said to have this

  • Affect all races, genetically predisposition


Medication cosmetics services which can cause photosensitivity
Medication / cosmetics /services which can cause photosensitivity

Drugs

  • Antibiotic

  • Antidepressants

  • Anti malarials

  • Anti arthritic drugs

  • Cortisone

    Beauty Services

  • Peels

  • Waxing

  • Body scrubs

  • Aromatherapy massage oils

Cosmetics

  • Perfumes

  • Aromatherapy oils

  • Fruit acids

  • Vitamin A –retin A

  • Acne medication-

  • Roaccutane


Advice
ADVICE photosensitivity


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