Areola
Overview
This article is about the breast tissue. For the entomology
Entomology
Entomology is the scientific study of insects, a branch of arthropodology...

 term, see the glossary of Lepidopteran terms. For an artistic cloud motif, see aureola
Aureola
An aureola or aureole is the radiance of luminous cloud which, in paintings of sacred personages, surrounds the whole figure...

. For the cactus feature, see Areole
Areole
Areoles are an important diagnostic feature of cacti, and identify them as a family distinct from other succulent plants. The areoles on cacti are clearly visible; they generally appear as small light- to dark-colored bumps, out of which grow clusters of spines...

.

In anatomy
Human anatomy
Human anatomy is primarily the scientific study of the morphology of the human body. Anatomy is subdivided into gross anatomy and microscopic anatomy. Gross anatomy is the study of anatomical structures that can be seen by the naked eye...

, an areola, plural areolae (diminutive of Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

 area, "open place") is any circular area such as the colored skin surrounding the nipple
Nipple
In its most general form, a nipple is a structure from which a fluid emanates. More specifically, it is the projection on the breasts or udder of a mammal by which breast milk is delivered to a mother's young. In this sense, it is often called a teat, especially when referring to non-humans, and...

. Although the term is most commonly used to describe the pigment
Pigment
A pigment is a material that changes the color of reflected or transmitted light as the result of wavelength-selective absorption. This physical process differs from fluorescence, phosphorescence, and other forms of luminescence, in which a material emits light.Many materials selectively absorb...

ed 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
Pimple
A pimple, zit or spot is a kind of acne, and one of the many results of excess oil getting trapped in the pores. Some of the varieties are pustules or papules....

.
Careful inspection of a mature human female nipple
Nipple
In its most general form, a nipple is a structure from which a fluid emanates. More specifically, it is the projection on the breasts or udder of a mammal by which breast milk is delivered to a mother's young. In this sense, it is often called a teat, especially when referring to non-humans, and...

 will reveal several small openings arranged radially around the tip of the nipple (lactiferous duct
Lactiferous duct
Lactiferous ducts lead from the lobules of the mammary gland to the tip of the nipple. They are also referred to as galactophores, galactophorous ducts, mammary ducts, mamillary ducts and milk ducts...

s) from which milk is released during lactation
Lactation
Lactation describes the secretion of milk from the mammary glands and the period of time that a mother lactates to feed her young. The process occurs in all female mammals, however it predates mammals. In humans the process of feeding milk is called breastfeeding or nursing...

.
Encyclopedia
This article is about the breast tissue. For the entomology
Entomology
Entomology is the scientific study of insects, a branch of arthropodology...

 term, see the glossary of Lepidopteran terms. For an artistic cloud motif, see aureola
Aureola
An aureola or aureole is the radiance of luminous cloud which, in paintings of sacred personages, surrounds the whole figure...

. For the cactus feature, see Areole
Areole
Areoles are an important diagnostic feature of cacti, and identify them as a family distinct from other succulent plants. The areoles on cacti are clearly visible; they generally appear as small light- to dark-colored bumps, out of which grow clusters of spines...

.

In anatomy
Human anatomy
Human anatomy is primarily the scientific study of the morphology of the human body. Anatomy is subdivided into gross anatomy and microscopic anatomy. Gross anatomy is the study of anatomical structures that can be seen by the naked eye...

, an areola, plural areolae (diminutive of Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

 area, "open place") is any circular area such as the colored skin surrounding the nipple
Nipple
In its most general form, a nipple is a structure from which a fluid emanates. More specifically, it is the projection on the breasts or udder of a mammal by which breast milk is delivered to a mother's young. In this sense, it is often called a teat, especially when referring to non-humans, and...

. Although the term is most commonly used to describe the pigment
Pigment
A pigment is a material that changes the color of reflected or transmitted light as the result of wavelength-selective absorption. This physical process differs from fluorescence, phosphorescence, and other forms of luminescence, in which a material emits light.Many materials selectively absorb...

ed 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
Pimple
A pimple, zit or spot is a kind of acne, and one of the many results of excess oil getting trapped in the pores. Some of the varieties are pustules or papules....

.

Human mammary areola

Careful inspection of a mature human female nipple
Nipple
In its most general form, a nipple is a structure from which a fluid emanates. More specifically, it is the projection on the breasts or udder of a mammal by which breast milk is delivered to a mother's young. In this sense, it is often called a teat, especially when referring to non-humans, and...

 will reveal several small openings arranged radially around the tip of the nipple (lactiferous duct
Lactiferous duct
Lactiferous ducts lead from the lobules of the mammary gland to the tip of the nipple. They are also referred to as galactophores, galactophorous ducts, mammary ducts, mamillary ducts and milk ducts...

s) from which milk is released during lactation
Lactation
Lactation describes the secretion of milk from the mammary glands and the period of time that a mother lactates to feed her young. The process occurs in all female mammals, however it predates mammals. In humans the process of feeding milk is called breastfeeding or nursing...

. Other small openings in the areola are sebaceous gland
Sebaceous gland
The sebaceous glands are microscopic glands in the skin that secrete an oily/waxy matter, called sebum, to lubricate and waterproof the skin and hair of mammals...

s, known as Montgomery's glands (or glands of Montgomery), which provide lubrication to protect the area around the nipple and assist with suckling
Breastfeeding
Breastfeeding is the feeding of an infant or young child with breast milk directly from female human breasts rather than from a baby bottle or other container. Babies have a sucking reflex that enables them to suck and swallow milk. It is recommended that mothers breastfeed for six months or...

 and pumping of the lactation. These can be quite obvious and raised above the surface of the areola, giving the appearance of "goose-flesh". This tissue, in addition to supporting the flow of milk, also bears the brunt of physical stress that the suckling involves.

Colour

Another reason for its colour comes from an abundance of two polymers: eumelanin (the brown pigment) and pheomelanin (the red pigment). The genetically-directed amount of these pigments determines the colour of the areola. They can range from pale yellow to nearly black, but generally tend to be paler among people with lighter skin tones and darker among people with darker skin tones.

Additionally, it has been claimed that a reason for the differing colour is to make the nipple area more visible to the infant.

An individual's areolae may also change colour over time in response to hormonal
Hormone
A hormone is a chemical released by a cell or a gland in one part of the body that sends out messages that affect cells in other parts of the organism. Only a small amount of hormone is required to alter cell metabolism. In essence, it is a chemical messenger that transports a signal from one...

 changes caused by menstruation
Menstruation
Menstruation is the shedding of the uterine lining . It occurs on a regular basis in sexually reproductive-age females of certain mammal species. This article focuses on human menstruation.-Overview:...

, certain medications, and aging
Ageing
Ageing or aging is the accumulation of changes in a person over time. Ageing in humans refers to a multidimensional process of physical, psychological, and social change. Some dimensions of ageing grow and expand over time, while others decline...

. Most notably, the areolae may darken substantially during pregnancy
Pregnancy
Pregnancy refers to the fertilization and development of one or more offspring, known as a fetus or embryo, in a woman's uterus. In a pregnancy, there can be multiple gestations, as in the case of twins or triplets...

—some regression to the original colour may occur after the baby is born, but again, this varies from individual to individual.

Size and shape

The size and shape of areolae are 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
Ellipse
In geometry, an ellipse is a plane curve that results from the intersection of a cone by a plane in a way that produces a closed curve. Circles are special cases of ellipses, obtained when the cutting plane is orthogonal to the cone's axis...

.

The average diameter
Diameter
In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints are on the circle. The diameters are the longest chords of the circle...

 of male areolae is around 25 mm (1 in). Sexually mature women have an average of 38.1 mm (1.5 in), but sizes range up to 100 mm (4 in) or greater. Lactating women, or women with particularly large breasts, may have even larger areolae.

Diseases

  • Paget's disease of the breast
    Paget's disease of the breast
    Paget's disease of the breast is a malignant condition that outwardly may have the appearance of eczema, with skin changes involving the nipple of the breast....

     is a malignant condition that outwardly may have the appearance of eczema
    Eczema
    Eczema is a form of dermatitis, or inflammation of the epidermis . In England, an estimated 5.7 million or about one in every nine people have been diagnosed with the disease by a clinician at some point in their lives.The term eczema is broadly applied to a range of persistent skin conditions...

    , with skin changes involving the areola and nipple.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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