skin tanning process in epidermis cross-section diagram

skin tan ultraviolet hyperpigmentation pigmentation melanin uv sun epidermis complexion process melanosome production melanocyte keratinocyte rays anatomy tone pigment dark light phototype vitiligo cell health medicine body people brown illustration eumelanin pheomelanin treatment dermatology cosmetology skincare melasma africanamerican asian caucasian hispanic structure tissue basal diagram crosssection vector infographic protection reduce