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Dermatology > Pigmentary System > Flashcards

Flashcards in Pigmentary System Deck (7)
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1

Where is melanin formed? What happens to it as cells mature?

- melanocytes produce melanosomes in basal layer of epidermis
- transferred to keratinocytes
- during anagen transerred to hair matrix cells
- as keratinocytes -> stratum coreum granules degraded by lysosomes.

2

2 types of melanin

> eumelanins
- black
- insoluble
- oval melonsomes
- much researched
> phaemelanins
- red bornw/yellow
- soluble in alkali
- round melanosomes
- little researched

3

Where must diseases affect in order to cuase pigmentary changes?

- hair matrix
- basal layer of epidermis

4

causes of hyperpigmentation?

- recent inflammation
- endocrine
- lentigo (macular melanosis in mature dogs, +- epidermal thickening)
- lentigo simplex (orange cats <1yr black spots on lips, gums, eyelids, nose)

5

Causes of hypopigmentation?

- damage to epidermis/hair follicle
- interface autoimmune disease
- viteligo (autoimmune attack against melanocytes)

6

2 causes of sunlight based skin damage?

1. excessive exposure on lightyl pigmented skin
2. photosensitivity or photoallergy (reaction of chemical promoted bu UV light)

7

causes of photosensitisation>

- administered drugs
- absorbed from food (plants)
- abnormal metabolism due to hepativ disease/genetic abnormalities