Question

What is the hormone responsible for the secretion of milk after parturition?
(a)ICSH
(b)Prolactin
(c)ACTH
(d)LH

Answer 1

The secretion of milk, also known as lactation, occurs from the mammary glands of the mother in the case of mammals and the mother feeds this milk to her young, which is called breastfeeding or nursing in humans. The lactating is a hormonal activity that is triggered by the stimulation in the nipples by the child.

Complete answer:
The hormone named prolactin is responsible for the secretion of milk in females after parturition. It is a large protein(hormone) produced and secreted mainly by the anterior part of the pituitary. The nipple stimulation during nursing a baby causes prolactin secretion and thus lactation in the mother.

Additional Information: Prolactin or PRL is the hormone that causes lactation in mammals by increasing growth and differentiation of the alveoli and influencing differentiation of ductal structure. Other than that prolactin has a wide range of activities in mammals as it has a broad distribution of specific receptors in target tissues and organs. Prolactin is produced and secreted in the anterior pituitary I.e. adenohypophysis and is found in both female and male individuals. It is also secreted by breasts, uterus, adipose tissue, and even sometimes skin. The main function of prolactin is to differentiate the cells that perform their specific functions. When our body is exposed to a high level of cortisol hormone, the production of prolactin takes place. It plays a vital role in controlling osmolarity and also involved in the formation of steroid hormones, fatal lung development, lactation, ductal growth of breasts, and also in the metabolism of certain compounds. In males, they increase the reproductive functions by synergies with other hormones such as LH and testosterone.
So, the correct answer is “prolactin”.

Note: The hormones that take part in the secretion of milk in humans are
-Progesterone (growth of lobes)
-Estrogen (growth of milk duct system)
-Prolactin (growth of alveoli and differentiation of ductal structure)
-HPL (instrumental in breast, nipple, and areola growth before birth)
-FSH, LH, and hCG (controls estrogen and progesterone level)
-GH (contributes to galactopoiesis of prolactin)
-ACTH and glucocorticoids (induce lactation)
-TSH and TRH (galactopoietic)
-Oxytocin (helps to squeeze newly produced milk into the duct system).