Skin color is determined largely by the amount of melanin pigment produced by melanocytes in the skin. Explain how differing degrees of pigmentation are produced Key Points
Key Terms
MelaninSkin color is largely determined by a pigment called melanin but other things are involved. Your skin is made up of three main layers, and the most superficial of these is called the epidermis. The epidermis itself is made up of several different layers.  Melanocyte: Cross-section of skin showing melanin in melanocytes The deepest of the epidermal layers is called the stratum basale or stratum germinativum. In this layer lie important cells called melanocytes. Their name is derived from two parts: melano-, which means black or darkness, and -cyte, which means cell. Melanocytes are irregularly shaped cells that produce and store a pigment called melanin. The most abundant type of melanin is called eumelanin. This pigment is stored in organelles called melanosomes. Eumelanin is responsible for the brown and black pigmentation of human skin or the lack thereof if little of it is produced. The production of melanin is called melanogenesis—genesis means formation or development. How Skin Color is DeterminedRegardless of background, every person has largely the same number of melanocytes, but the genetics of each person is what determines how much melanin is produced and how it is distributed throughout the skin. For example, light skinned individuals may have darker places like nipples and moles. Conversely, dark skinned individuals have a lighter tone to the palms of their hands. Another critical factor, exposure to sunlight, triggers the production of melanin as well. This is what gives us a tan. The melanin produced in response to the sun’s rays protects our skin and the rest of the body from the harmful effects of the sun’s burn and cancer-inducing U.V. radiation. The Role of KeratinocytesPeople with darker skin have more active melanocytes compared to people with lighter skin. However, the pigment of our skin also involves the most abundant cells of our epidermis, the keratinocytes. While melanocytes produce, store, and release melanin, keratinocytes are the largest recipients of this pigment. The transfer of melanin from melanocytes to keratinocytes occurs thanks to the long tentacles each melanocyte extends to upwards of 40 keratinocytes. If a person is unable to produce melanin, they have a condition called albinism. Other Skin Color DeterminantsTanned Skin: Exposure to UV radiation through tanning causes changes in the pigmentation of the skin by increasing melanin production. Besides melanin, other factors play a role in general or local skin color. These include:
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What are the factors that determine skin color?Skin color is determined mainly by the amount and distribution of melanin, a pigmented polymer produced by melanocytes. Hyperpigmentation is almost always the result of either production of too much melanin or abnormal distribution of pigment, although heavy metals or drug metabolites can change skin color.
What two factors determine melanin?Some of the factors that affect melanin production include the following:. Exposure to Ultraviolet Radiation: In general, those who are more often exposed to ultraviolet light will have darker skin. ... . Genetics: Unsurprisingly, genetics plays a huge role in determining melanin levels.. What factors affect melanin production?The types and amounts of melanin produced by melanocytes are determined genetically and are influenced by a variety of extrinsic and intrinsic factors such as hormonal changes, inflammation, age and exposure to UV light. These stimuli affect the different pathways in melanogenesis.
What does melanin determine?Melanin is responsible for determining skin and hair colour and is present in the skin to varying degrees, depending on how much a population has been exposed to the sun historically.
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Name the factors that determine skin color and describe the function of melanin.
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