Skin Pigmentation: Hemoglobin, Carotenes, and Melanin

Hemoglobin

A protein in red blood cells that carries oxygen, contributing a reddish or pinkish hue to the skin, especially in individuals with lower melanin concentrations.

Carotenes

Lipid-soluble plant pigments that accumulate in the stratum corneum and subcutaneous fat, contributing an orange-yellow tint to the skin and are precursors to Vitamin A.

Melanin

The most significant pigment determining skin color, a polymer produced by melanocytes, contributing to colors from yellowish-brown to dark brown and black, and providing protection against UV radiation.

Melanocytes

Specialized cells located in the stratum basale responsible for synthesizing melanin within organelles called melanosomes.

Melanosomes

Organelles within melanocytes where melanin is produced and then transferred to keratinocytes.

Genetic Influence on Melanin

The inherited predisposition that largely determines the amount of melanin an individual produces, controlling melanocyte number, activity, and melanin type.

Environmental Influence (UV Radiation)

A major factor that increases melanin production; UV light stimulates melanocytes to produce more melanin as a protective response, leading to tanning or darkening of the skin.