Areolar glands, also known as glandulae areolares, Montgomery glands, and tubercula areolae, are 10-15 elevations found on the

areola The human areola (''areola mammae'', or ) is the pigmented area on the breast around the nipple. More generally, an areola is a small circular area on the Human body, body with a different histology from the surrounding Tissue (biology), tissue ...

. They are usually arranged in a circle around the

nipple The nipple is a raised region of tissue on the surface of the breast from which, in lactating females, breast milk, milk from the mammary gland leaves the body through the lactiferous ducts to Breastfeeding, nurse an infant. The milk can flow th ...

, and can be particularly visible when the nipple is erect. Their role is to promote adequate

breastfeeding Breastfeeding, also known as nursing, is the process where breast milk is fed to a child. Infants may suck the milk directly from the breast, or milk may be extracted with a Breast pump, pump and then fed to the infant. The World Health Orga ...

of the infant. They are

sebaceous gland A sebaceous gland or oil gland is a microscopic exocrine gland in the skin that opens into a hair follicle to secrete an oily or waxy matter, called sebum, which lubricates the hair and skin of mammals. In humans, sebaceous glands occur in ...

s, which secrete sebum oil that is a

free fatty acid In chemistry, in particular in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated or unsaturated. Most naturally occurring fatty acids have an unbranched chain of an even number of carbon atoms, f ...

onto the skin that lubricates the nipple when breastfeeding, protects the skin, and provides some air tightness between the infant's mouth and the nipple. They also emit odor compounds into the air that attract babies. In addition, a study of 121

white White is the lightest color and is achromatic (having no chroma). It is the color of objects such as snow, chalk, and milk, and is the opposite of black. White objects fully (or almost fully) reflect and scatter all the visible wa ...

mothers found that higher numbers of areolar glands on the breasts (commonly known as AG number) was

correlated In statistics, correlation or dependence is any statistical relationship, whether causal or not, between two random variables or bivariate data. Although in the broadest sense, "correlation" may indicate any type of association, in statistic ...

with infants gaining weight faster and lactation beginning faster. A meta-analysis shows that odor compounds emitted from lactating breasts reduced arousal states in active newborns, increases arousal states in sleepy newborns, and causes babies to turn their heads towards the breast, though the source of these effects were not strongly identified. A targeted study of 16 infants based on these observations has shown that these effects can be induced experimentally through a researcher directing a baby with areolar gland scent on a stick. Additionally, areolar gland scents cause these effects more strongly than milk or sebum odors.

Structure

Areolar glands are round bumps found in the

, and sometimes on the

Variation

The tubercles become more pronounced when the nipple is erect, and during

pregnancy Pregnancy is the time during which one or more offspring gestation, gestates inside a woman's uterus. A multiple birth, multiple pregnancy involves more than one offspring, such as with twins. Conception (biology), Conception usually occurs ...

. The number of glands can vary greatly, usually averaging from 4 to 28 per

breast The breasts are two prominences located on the upper ventral region of the torso among humans and other primates. Both sexes develop breasts from the same embryology, embryological tissues. The relative size and development of the breasts is ...

Function

Areolar glands make oily secretions (lipoid fluid) that keep the areola and the nipple lubricated and protected. Volatile compounds in these secretions may also serve as an olfactory stimulus for newborn appetite. Areolar glands, especially during pregnancy and lactation, emit odors that reliably cause newborn babies to face the breast and locate the nipple. Cleaning the breast or otherwise masking these scents makes it harder for newborns to find the nipple, and to get an important first drink of immunoprotective

colostrum Colostrum (, of unknown origin) is the first form of milk produced by the mammary glands of humans and other mammals immediately following delivery of the newborn. Animal colostrum may be called beestings, the traditional word from Old English ...

. They can become exposed and raised when the nipple is stimulated. The skin over the surface opening is lubricated and tends to be smoother than the rest of the areola.

Clinical significance

Areolar glands may secrete excessive amounts of oil. This is a neutral condition that rarely represents any underlying problem, unlike the spontaneous flow of milk from the breast.

History

Areolar glands may also be called glands of Montgomery, or Montgomery tubercles. They are named after Dr. William Fetherstone Montgomery (1797–1859), an Irish

obstetrician Obstetrics is the field of study concentrated on pregnancy, childbirth and the postpartum period. As a medical specialty, obstetrics is combined with gynecology under the discipline known as obstetrics and gynecology (OB/GYN), which is a surgi ...

who first described them in 1837.

References