What affects female breast development

　　Effects of anterior pituitary hormones on breast development The anterior pituitary gland and the ovaries maintain a functional regulatory relationship with each other under normal circumstances. When ovarian function is low, the function of the anterior pituitary gland is enhanced; conversely, when ovarian function is hyperactive, the function of the anterior pituitary gland is decreased.

　　Pregnant women, although there are often many hormones in the body to promote mammary gland development, their mammary glands still do not have acini. The breasts are composed of many long mammary gland ducts, which means that the breasts have not yet developed. Only after pregnancy, the estrogen in the blood increases greatly. Due to the increase in estrogen, the mammary gland ducts grow very long and give birth to many branches. The increase in progesterone in the blood causes the acini at the end of the glandular ducts to gradually increase and the lobules to gradually develop. At this time, the mammary glands swell even more. Experiments have also proven that estrogen mainly stimulates the proliferation of mammary gland ducts, while progesterone promotes the development of acini. However, these two hormones alone cannot fully develop the breasts. The participation of anterior pituitary hormones, that is, growth hormone, glucocorticoid (or ACTH) and prolactin, etc., must work together to fully develop the breasts.

　　What are the effects of ovarian hormones on breast development? female After puberty, the follicles in the ovaries mature and secrete a large amount of estrogen. At this time, the mammary glands develop rapidly and become significantly enlarged. This function is under the control of hormones from the anterior pituitary gland so that estrogen can work. The amount of estrogen is directly proportional to the regeneration of milk ducts within a certain range. Excessive estrogen will not only fail to promote the development of the mammary gland, but will also inhibit the development of the mammary gland. This is because large amounts of estrogen inhibit the secretory function of the anterior pituitary gland. The secretion of gonadotropins from the anterior pituitary gland is reduced, which also causes the endocrine function of the ovaries to be low, thus affecting the development of the mammary gland.

　　Before the ovary secretes progesterone, the development of glandular lobules is extremely limited. After sexual maturity, especially during pregnancy, the gland lobules can fully develop under the combined and repeated effects of progesterone and estrogen. The development of glandular lobules requires a certain intensity of hormonal stimulation and the action of an appropriate proportion of estrogen and progesterone. Otherwise, the epithelial cells of the terminal milk ducts are prone to abnormalities, such as cystic hyperplasia.

　　Effects of Adrenocortical Hormones on Breast Development. The adrenal cortex secretes a variety of hormones, including hormones that can regulate sexual characteristics. male There are adrenosterone and ketones for men, and progesterone and estrogen for women. Therefore, when the adrenal cortex hyperplases or tumors occur, it can stimulate the development of male and female breasts in childhood. If the adrenal glands of lactating animals are removed, lactation can be stopped. If corticosteroids are injected again, lactation function can be restored.

　　What is the impact of the thyroid gland on mammary gland development? In young children with hypothyroidism, the whole body will be underdeveloped and the mammary glands will not develop. If thyroid preparations are given, the whole body development and mammary gland development will be normal. The effect of the thyroid gland on the breast is indirect. When the thyrotropin secreted by the anterior pituitary gland decreases, thyroxine secretion decreases and breast development is affected.