why estrogen and progestrone inhibits secretion of milk from breast but prolactin stimulates it
Estrogen and progesterone are hormones produced during the menstrual cycle and pregnancy. They play important roles in regulating the reproductive system. During pregnancy, high levels of estrogen and progesterone maintain the structure of the milk ducts in the breast and prepare them for milk production.
However, estrogen and progesterone also have inhibitory effects on lactation, or the process of milk production. They prevent the full expression of lactation by inhibiting the release of prolactin, a hormone necessary for milk synthesis. This inhibition serves to prevent milk production before childbirth.
After childbirth, the levels of estrogen and progesterone decrease significantly, while the level of prolactin increases. Prolactin is the primary hormone responsible for milk production and secretion in the breast. When the nipple is stimulated, prolactin is released, which signals the mammary glands to produce milk. This allows for the initiation and maintenance of lactation.
In summary, estrogen and progesterone inhibit milk secretion from the breast by suppressing prolactin release, while prolactin stimulates milk production after childbirth when estrogen and progesterone levels drop.
Estrogen and progesterone play important roles in the development of mammary glands during pregnancy, but they inhibit the secretion of milk. Here's a step-by-step explanation:
1. Mammary gland development: During pregnancy, estrogen and progesterone stimulate the growth and development of mammary glands in preparation for milk production.
2. Inhibition of milk secretion: While estrogen and progesterone promote the growth of mammary glands, they also suppress the production and release of milk. These hormones prevent the secretion of milk by inhibiting the action of prolactin.
3. Prolactin's role: Prolactin is a hormone secreted by the pituitary gland that stimulates the production of milk. Its levels increase during pregnancy, preparing the mammary glands for lactation.
4. Hormonal changes after birth: After childbirth, the levels of estrogen and progesterone decline, while prolactin levels remain high. This hormonal shift removes the inhibitory effects of estrogen and progesterone, allowing prolactin to stimulate milk production and secretion.
In summary, while estrogen and progesterone promote mammary gland development, they inhibit milk secretion after childbirth. On the other hand, prolactin stimulates milk production and is responsible for the initiation and maintenance of breastfeeding.
Estrogen and progesterone are hormones that play important roles in the female reproductive system. During pregnancy, high levels of estrogen and progesterone are produced to prepare the breasts for milk production. However, these hormones actually inhibit the secretion of milk from the breasts.
The primary reason for this inhibition is that estrogen and progesterone block the action of another hormone called prolactin. Prolactin is responsible for stimulating the production of milk in the breast tissue. When estrogen and progesterone levels decrease after childbirth, the inhibition is lifted, and prolactin is then able to stimulate milk production.
So, to summarize:
1. During pregnancy, high levels of estrogen and progesterone are produced.
2. These hormones inhibit the secretion of milk from the breasts.
3. Estrogen and progesterone block the action of prolactin.
4. After childbirth, estrogen and progesterone levels decrease.
5. The inhibition is lifted, and prolactin can stimulate milk production.
To get this information, you can study the physiology of lactation or consult reliable medical resources such as textbooks, research papers, or trusted websites focusing on reproductive biology or lactation.