Question

Milk ejection hormone in a lactating mother is-
A. Prolactin
B. Oxytocin
C. Progesterone
D. Estrogen

Answer 1

Hint: Lactation is described as the secretion of milk from the mammary glands. It is regulated by the secretions of the posterior part of the pituitary gland that induce strong contraction in muscles of the uterine cavity.

Complete answer:
Oxytocin is known as the milk ejection hormone. The oxytocin reflex which is also sometimes called the ‘milk let-down reflex’ or the ‘milk ejection reflex’ is responsible for the process of ejection of milk from the mother’s body. Oxytocin is produced more quickly than prolactin. It helps in the ejection of the milk that is already formed in the breast.
The breast comprises 15-20 sections or lobes which is further divided into various lobules. The milk is formed by the alveoli present inside the lobules. Each lobule opens into a duct which in return opens into the lobar ducts or the lactiferous duct. These ducts converge at the skin and open into the nipple. The suction of milk by the baby acts as a stimulus for the release of milk. The process naturally occurs in all post-pregnant female mammals.
Besides oxytocin, prolactin also plays a major physiological role. The main functions of prolactin are-
> It stimulates milk production.
> It has an important role in breast development along with estrogen and progesterone.
> It stimulates breast growth and enlargement of the alveoli in preparation for lactation.
> In males, it stimulates the release of Luteinising hormone that results in the release of testosterone.

Note:
- New-born infants, at times, produce some amount of milk from their own breast tissue which is known as witch’s milk.
- Oxytocin also plays an important role in the contraction of the womb (uterus) during childbirth.
- Inside the mammary gland, the milk remains stored inside the lactiferous sinus.