The breasts are not a part of the woman’s genitals. They develop as a result of the action of the sexual hormones that manifest in puberty.
However, this does not mean that they do not take part in the erotic life of the woman, through their important psychological role.
The breasts are first of all important for breast-feeding the baby, apart from the usual erotic pleasure.
THE CONSTITUTION OF THE BREASTS
The mammal gland is usually “in pause”, except for the interval of pregnancy and breast-feeding. The main constituents of the breast are the conjunctive tissue, rich in elastic fibers and the adipose tissue, rich in fat.
Each breast has 15 to 20 sections, called lobes that are arranged like the petals of a daisy. Each lobe has many smaller lobules, which end in dozens of tiny bulbs that can produce milk.
The lobes, lobules, and bulbs are all linked by thin tubes called ducts.
These ducts lead to the nipple in the center of a dark area of skin called the areola. Fat fills the spaces between lobules and ducts.
There are no muscles in the breast, but muscles lie under each breast and cover the ribs.
Each breast also contains blood vessels and vessels that carry lymph. The lymph vessels lead to small bean-shaped organs called lymph nodes, clusters of which are found under the arm, above the collarbone, and in the chest, as well as in many other parts of the body.
ANATOMY AND PHYSIOLOGY
Each of these accessory reproductive glands lies on the superior surface of the chest wall lying mostly on top of the pectoral’s muscle.
During pregnancy the alveoli enlarge and during lactation the cells secrete milk substances, i.e. proteins and lipids. The cells surrounding the alveoli contract to express the milk during lactation.
Breast tissue is supported by ligaments called Coopers ligaments that keep the breasts in their characteristic shape and position. In the case of older women or in pregnancy these ligaments become loose or stretched, respectively, and the breasts sag.
Reproductive hormones are important in the development of the breast in puberty and in lactation. Estrogen promotes the growth of the gland and ducts while progesterone stimulates the development of milk producing cells.
Prolactin, released from the anterior pituitary gland, stimulates milk production. Oxytocin, released from the posterior pituitary in response to suckling, causes milk ejection from the lactating breast.
In response to hormone stimulation, the breasts enlarge due to the growth of ductal and alveolar tissues and an increase in fat deposits. The nipple and areola also enlarge and become more sensitive to touch.
When the woman begins to menstruate, the breasts undergo a periodic premenstrual phase that varies with the individual but can include an increase in size, swelling and tenderness.
The symptoms subside within a few days of the onset of bleeding. During pregnancy, the breasts increase in size dramatically due to the influence of progesterone.
The nipple and areola become deeply pigmented and increase in size. The necessary machinery to produce milk by late pregnancy replaces most of the fat. After delivery the breasts begin to secrete milk.
The gland rapidly returns to the pre-pregnant state when nursing ceases. The postmenopausal breast may retain its shape but the milk producing machinery is mostly replaced by fat.
Nonetheless, the mammal gland gets its definitive structure only during pregnancy.
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