@instituteofhumananatomy: PART 2: The Cellular Truth About Skin Color (It's Not What You Think) Zooming into that paper-thin epidermis to understand what's actually happening at the cellular level. THE CELL BREAKDOWN: 90% of epidermal cells are keratinocytes - they produce keratin for protection and bind cells together 8% are melanocytes - they produce melanin (the pigment) THE LAYERS: Stratum basale (bottom layer): Single row of constantly dividing keratinocytes with melanocytes interspersed Stratum spinosum (above): 8-10 cell layers thick where melanocytes also deposit pigment HERE'S THE SHOCKING PART: Everyone has roughly the same number of melanocytes regardless of skin tone. Light skin, dark skin - about 8% of your epidermal cells are melanocytes. The difference? Activity level and melanin production at baseline. HOW IT WORKS: Each melanocyte has cytoplasmic extensions (like little arms) that contact up to 30 keratinocytes. They deposit melanin into these cells, giving them color. More melanin = darker pigmentation. TANNING EXPLAINED: UV exposure stimulates melanocytes to produce MORE melanin, protecting DNA from damage. This is why darker-skinned individuals have better natural protection against skin cancer. When you stop getting sun exposure, those darker keratinocytes eventually flake off and new, lighter ones replace them. Want to maintain a tan? You need constant UV stimulation. THE PROTECTIVE MECHANISM: Melanin shields the nucleus and DNA inside keratinocytes from UV damage and potential mutations. It's your body's natural sunscreen. Coming up in Part 3: Why palm pigmentation differs and the sun damage connection. Visit the link in our bio for 60% off our "Understanding Skin" eBook! #Melanocytes #Keratinocytes #SkinPigmentation #Melanin #UVProtection #Epidermis #Tanning #SkinScience
