MELANOCYTES Derived from neural crest cells Network in basal and suprabasal position Epidermal melanin unit = 1 melanocyte for 36 keratinocytes Melaninocyte injects the pigment to the keratinocytes: the latter hold most of the melanin but do not make the melanosome organelles from which it is dervied Divide under stimuli Produce and transfer melanosomes A melanosome is an organelle in animal cells, and is the cellular site of synthesis, storage and transport of melanin MELANIN Eumelanin Black, insoluble Phaeomelanin Red. red hair. Feathers of red hens Both Derived from tyrosine by tyrosinase Share initial steps of synthesis SYNTHESIS OF EUMELANIN: SYNTHESIS OF PHAEOMELANIN: Use sunscreen every day to prevent aging effects FUNCTIONS OF MELANIN Avoids damage to DNA of keratinocytes Decreases cutaneous carcinogenesis Eliminates genetically damaged cells Prevents ageing of the skin TANNING Immediate Oxidation of pre-formed melanin
MELANOCYTES Derived from neural crest cells Network in basal and suprabasal position Epidermal melanin unit = 1 melanocyte for 36 keratinocytes Melaninocyte injects the pigment to the keratinocytes: the latter hold most of the melanin but do not make the melanosome organelles from which it is dervied Divide under stimuli Produce and transfer melanosomes A melanosome is an organelle in animal cells, and is the cellular site of synthesis, storage and transport of melanin MELANIN Eumelanin Black, insoluble Phaeomelanin Red. red hair. Feathers of red hens Both Derived from tyrosine by tyrosinase Share initial steps of synthesis SYNTHESIS OF EUMELANIN: SYNTHESIS OF PHAEOMELANIN: Use sunscreen every day to prevent aging effects FUNCTIONS OF MELANIN Avoids damage to DNA of keratinocytes Decreases cutaneous carcinogenesis Eliminates genetically damaged cells Prevents ageing of the skin TANNING Immediate Oxidation of pre-formed melanin
Dermatology-notes-BETA.docx