787 pages on this wiki. Mark Andrew Spitz (born February 10, 1950) is a retired American swimmer. He won seven gold medals at the 1972 Summer Olympics, an achievement only surpassed by Michael Phelps who won eight golds at the 2008 Olympics.Spitz set new world records in all seven events in which he competed, a record that still stands.87 pages on this wiki. Mark Andrew Spitz (born February 10, 1950) is a retired American swimmer. He won seven gold medals at the 1972 Summer Olympics, an achievement only surpassed by Michael Phelps who won eight golds at the 2008 Olympics.
The colour of the skin is determined by the concentrations of three main pigments: melanin, carotene and haemoglobin. These are found in the dermis and combine to produce the pigmentation of all surface tissues including the skin, mucous membranes, and even the eyes.
For a review of mechanism of action of skin whitening agents, see Chang (2012) or Ebanks, Wickett, Boissy (2009). Melanin is the main substance responsible for the color of the skin. Melanin is class of dark polymers generated by the body through the process of melanogenesis. Among the melanin pigmenting the skin and hair, 2 types can be distinguished based on its chemical composition and biological route of synthesis: the black/brown eumelanin and the red/yellow pheomelanin.