The breast

Breast are glands that have as main function to produce the breast milk for a newborn child.

Composition:

ACINO – the smaller part of this gland, responsible for the milk production at the lactation period;

MILK-PRODUCING LOBES – comprised by the set of acinos;

MAMMARY LOBES – set of mammary lobules that connect to the ampulla by a duct;

MAMMARY DUCTS – are from 15 to 20 ducts that transport milk to the ampulla;

GLANDS TISSUE – set of lobes and ducts;

AMPULLA – elastic protuberance where the mammary ducts are;

AREOLA – central breast structure where the ampulla is;

FAT TISSUE – fat tissue that covers the breast, and is comprised accordingly with the woman’s biotype, alimentation and age.

Nipple and areola

Looking from the outside, each breast has, at its central portion, one areola and one nipple (mammary ampulla), comprised by 15 to 20 ducts. The nipple skin is pigmented, wrinkled and rough, due to the presence of sebaceous glands, producing small elevations on the surface.

Size, form and density

Size, form, nipples and areola can differ individually from woman to woman. The differences among breasts are minimal and unimportant. When are small, the breasts have low weight and tend to be tall and upright, staying away from the thorax wall. When they are large, they are heavy and tend to touch the thorax wall. When are young, women present breasts with more glands tissue volume, being sounder and dense. When menopause period is approaching, this tissue is atrophying and being progressively replaced by fat tissue, to finally become almost exclusively fat and glands tissue remains, when reaching the post-menopause period.

Development cycle

As of the childhood, girls present a small elevation at the mammary region due to the presence of a rudimentary mammary tissue. When in puberty, hormones start to act more.

At the adult phase, stimulated by estrogen and progesterone cycles, they make the breasts swell during the menstrual period because they retain more fluids. Progesterone action at the second phase of the menstrual cycle, generates fluid retention at the organism, visibly in the breasts, causing swoleness, hardening and pain to them. But at menopause, often the gland atrophies and the parenchymal tissue is replaced by fat at the breasts.

Due to the several hormone levels, breasts react to the cycles month by month, suffering changes. Estrogen comes to strengthen the breast, generating a greater fluid retention and vascularization, making them swell and providing the multiplication of their cells. All of this is a preparation for the pregnancy, that is, for the possibility of generating the breast milk in case of fecundation and, in case this does not happen, the swelling will pass and everything goes back to what it was before.

Vascularization
The breast is irrigated by the mammary artery and some branches of the axillary artery. From the mammary artery we have the branches that drill and go cross the four intercostal spaces, commonly two vessels per space that trespass the chest muscle, reaching the breast from behind. Axillary branches of mammary vascularization are the subscapular artery, external thoracic artery and the acromiothoraxic artery.