Breast Development and Anatomy

Read more about the breast development in women, from childhood and puberty to menopause...

 

Female breasts start developing under the influence of the hormones produced in the ovaries.

 

The female breast is basically a mammary gland that produces milk after childbirth. Milk is produced in microscopic alveoli, and a cluster of alveoli is called a lobule. Lobules are connected to smaller canals called ductiles which merge into the larger lactiferous ducts that end in the breast’s nipple. Lobules in ducts are separated from the stroma by a special layer called the basement membrane.

 

Breast development starts in the womb.

Breast development in the foetus

Breast development starts in the womb. In the fifth week of foetal development, the epidermis thickens into two ribbon-like structures that rise from hand buds to leg buds of the embryo. This structure is called a mammary ridge. In further development of the foetus, a large extent of the ridge disappears and only the part in the thorax remains, later forming the mammary gland.

Between the twelfth and sixteenth week, cells are formed into nipple muscle, forming areolas. In the last trimester of pregnancy, the sex hormones of the placenta are passed to the blood circulation of the foetus.

Breast development in childhood

In childhood, breast development is proportional to the growth of the entire body, and this is true for both sexes. In boys, breasts remain on the childhood level of development for the whole life, while female breasts start developing under the influence of the hormones produced in the ovaries. The initial development of the breasts of a girl is called telarche.

Breast development in puberty

In puberty, hypothalamus (endocrine gland located in the brain) starts producing and releasing sex hormones that have an impact on the functioning of the pituitary gland or hypophysis. The hormones cause the growth of sexual organs as well as breasts in women. In puberty, the female nipple thickens and fatty tissue starts accumulating in the breast.

Breast shrinks at the end of the breastfeeding period. (jlp)

Fertile period

In the fertile period, the breast is under the influence of cyclic changes arising due to the change in the level of hormones in the menstrual cycle. Hormones have an impact on the breast through the receptors in cells.

In the fertile period, the breast is under the influence of cyclic changes in the level of hormones in the menstrual cycle. (jlp)

Breast shrinking

This occurs at the end of breastfeeding. The glandular parts shrink and a number of cells decay. As glandular tissue shrinks, the share of fatty tissue and the stroma increases. The breast returns to the inactive level.

Breast and the menopause

The functions of the ovaries start declining in late pre-menopause. This also indicates breast regression. There is not a lot of glandular tissue left in the breast in the last stage of regression.

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