Breast Structure and Hormonal Control

<p>They return to nonpregnant levels. (A)</p> Signup and view all the answers

<p>Suppression of ovulation. (C)</p> Signup and view all the answers

<p>Basal prolactin levels return to nonpregnant levels. (B)</p> Signup and view all the answers

<p>It is a method of contraception. (B)</p> Signup and view all the answers

<p>Prolactin (A)</p> Signup and view all the answers

<p>Interferes with prolactin binding to alveolar cells (A)</p> Signup and view all the answers

<p>By the fifth week of pregnancy (D)</p> Signup and view all the answers

<p>Nervous signals from the nipples to the hypothalamus (C)</p> Signup and view all the answers

<p>They surge each time the baby suckles (A)</p> Signup and view all the answers

<p>Prolactin (B)</p> Signup and view all the answers

<p>It regulates FSH and LH secretion (A)</p> Signup and view all the answers

<p>They decrease to nonpregnant levels (B)</p> Signup and view all the answers

<p>It can suppress ovulation due to high prolactin levels (B)</p> Signup and view all the answers

<p>Alveoli (B)</p> Signup and view all the answers

<p>Prolactin (A)</p> Signup and view all the answers

The structures involved in milk production and delivery within the breast, including lobules, alveoli, and lactiferous ducts.

Estrogen and progesterone stimulate breast development during pregnancy, but they also suppress milk production.

Prolactin is the hormone primarily responsible for milk production. It is produced by the anterior pituitary gland and its levels increase significantly during pregnancy.

Prolactin is inhibited by progesterone during pregnancy, preventing milk production until after birth.

Suckling triggers a surge in prolactin release, stimulating milk production after birth.

Prolactin levels decrease to normal levels after a few weeks postpartum, but each nursing session stimulates a temporary rise.

High levels of prolactin during lactation suppress ovulation, making breastfeeding a natural form of contraception.

Prolactin is regulated by the hypothalamus, which releases GnRH, ultimately influencing prolactin production.

The mammary gland is responsible for milk production and consists of lobules, alveoli, and lactiferous ducts. Lobules are clusters of alveoli, which are tiny sacs lined with cells that secrete milk.

Estrogen and progesterone, essential for breast growth during pregnancy, surprisingly inhibit milk production. They prevent prolactin from binding to receptors in the breast, blocking milk secretion.

Prolactin, produced by the anterior pituitary gland, is the key hormone for milk production. Its levels increase significantly during pregnancy and surge even more after birth.

During pregnancy, progesterone blocks prolactin from binding to breast cells, preventing milk production. This ensures the fetus receives nourishment without premature milk release.

Suckling by the baby triggers a surge in prolactin production, increasing milk volume. This surge lasts for about an hour and repeats with each feeding session.

High prolactin levels during lactation suppress ovulation, making breastfeeding a natural form of contraception. This is not 100% effective, but can offer some family planning benefits.

As lactation continues, prolactin levels remain elevated, suppressing ovulation. This natural contraceptive effect is not 100% reliable but is helpful in some populations.