Areola



In anatomy, the term areola, plural areolae, (diminutive of Latin area, "open place") is used to describe any small circular area such as the colored skin surrounding the nipple. While it is most commonly used to describe the pigmented area around the human nipple (areola mammae), it can also be used to describe other small circular areas such as the inflamed region surrounding a pimple.

The Merriam-Webster dictionary notes two pronunciations for the term areola; aREola and areOla, with speaker icon pronunciations.

The reason the color of the areola differs from that of the rest of the breast is that the areola roughly delineates where the ducts of the mammary glands are. Careful inspection of a mature human female nipple will reveal several small openings arranged radially around the tip of the nipple (lactiferous ducts) from where milk is released during lactation. Other small openings in the areola are sebaceous glands known as Montgomery's glands (or glands of Montgomery) which provide lubrication to protect the area around the nipple and assist with suckling during lactation. These can be quite obvious and raised above the surface of the areola, giving the appearance of "goose-flesh".

Two polymers contribute to the color of the areola in humans - brown eumelanin and pheomelanin, a red pigment. The relative amount of these pigments determines the color of the areola, which can vary greatly, ranging from pale pink to dark brown, but generally tending to be paler among people with lighter skin tones and darker among people with darker skin tones.

An individual's areolae may also change color over time in response to hormonal changes caused by menstruation, certain medications, and ageing. Most notably, the areolae may darken substantially during pregnancy. Some regression to the original color may occur after the baby is born but, again, this varies from individual to individual.

The size and shape of areolae is also highly variable, with those of sexually mature women usually being larger than those of men and prepubescent girls. Human areolae are mostly circular in shape but many women and some men have areolae that are noticeably elliptical.

The areolae of most men is around 25 mm (1 in) in diameter while those of sexually-mature women may range up to 100 mm (4 in) or more in diameter, with average sizes around 30 mm (1 3/8 in). The areola of women who are lactating or who have particularly large breasts may be even larger.