Which hormone is essential for the production of milk in a mother's breast?

UPPSC-2021

Obstetrics & Gynaecology

Easy

Appeared in: UPPSC-2021

Explanation

Prolactin is the key hormone responsible for lactogenesis, which is the synthesis and secretion of milk from the alveolar cells of the mammary glands.
It is secreted by the anterior pituitary gland, and its levels rise significantly during pregnancy to prepare the breasts for lactation.
After delivery, the drop in estrogen and progesterone allows prolactin to act unopposed, initiating copious milk production.
The suckling stimulus from the baby maintains high prolactin levels, ensuring a continuous supply of milk.

Option A: Follicle-Stimulating Hormone (F.S.H.) is primarily involved in the reproductive cycle, stimulating the growth and maturation of ovarian follicles. It does not have a direct role in milk production.
Option C: Antidiuretic Hormone (A.D.H.), also known as vasopressin, is primarily responsible for regulating water balance by increasing water reabsorption in the kidneys. It is not involved in lactation.
Option D: Oxytocin is responsible for the milk ejection or 'let-down' reflex. It causes the myoepithelial cells surrounding the alveoli to contract, squeezing the already-produced milk into the ducts so the baby can access it. It does not synthesize the milk.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Hormonal control of lactation as background academic context rather than a clinical decision trigger.
Nurses play a vital role in educating new mothers about lactation. Explaining that frequent suckling or pumping is necessary to stimulate prolactin is key to establishing and maintaining a good milk supply.
Understanding the difference between prolactin and oxytocin helps in troubleshooting breastfeeding issues. For example, a mother might be producing enough milk (prolactin is working) but have trouble with let-down (oxytocin reflex may be inhibited by stress or pain).
What if? If a non-pregnant, non-lactating patient presents with milky nipple discharge (galactorrhea), a nurse should recognize this could be a sign of hyperprolactinemia, often caused by a pituitary adenoma (prolactinoma), and requires medical evaluation.

How to Approach the Question

First, identify the keywords in the question: 'hormone' and 'production of milk'.
The key is to differentiate between the 'production' of milk and the 'ejection' (or let-down) of milk. These are two separate processes controlled by different hormones.
Recall the primary functions of the hormones listed in the options.
Eliminate hormones not directly related to lactation. F.S.H. is for the ovarian cycle, and A.D.H. is for water balance.
This leaves Prolactin and Oxytocin. Remember the mnemonic: Prolactin Produces milk, and Oxytocin gets it Out.
Since the question asks for the hormone responsible for 'production', select Prolactin.

Concept Tested & Keywords

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E6 Physiology Guyton 4SAE Part 3 p. 69-71

E6 Physiology Essentials Sembulingam 10e Part 2 p. 150-152

E6 Obstetrics Williams p. 48-68