Prolactin reflex in mother causes?

RUHS, Jaipur, PB B.Sc Nursing Entrance-2018

Applied Physiology

Easy

Appeared in: RUHS, Jaipur, PB B.Sc Nursing Entrance-2018

Explanation

The prolactin reflex is the primary hormonal mechanism responsible for the synthesis and secretion of milk by the mammary glands.
Suckling by the infant stimulates nerve endings in the nipple, which signals the hypothalamus to reduce the secretion of dopamine (Prolactin Inhibiting Hormone).
This reduction in dopamine allows the anterior pituitary gland to release prolactin into the bloodstream.
Prolactin then acts on the alveolar cells of the breasts, stimulating them to produce milk for the next feeding.

Option A: Milk ejection, also known as the 'let-down' reflex, is caused by the hormone oxytocin, not prolactin. Oxytocin causes myoepithelial cells around the alveoli to contract, forcing milk into the ducts.
Option C: The prolactin reflex stimulates, rather than suppresses, milk production. Suppression is typically caused by high levels of dopamine, stress, or infrequent/ineffective removal of milk from the breast.
Option D: Milk is stored within the alveoli and ducts of the breast, but this is a passive state, not the direct result of the prolactin reflex. The reflex's purpose is to create the milk that will be stored.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Physiology of lactation and the role of hormonal reflexes as background academic context rather than a clinical decision trigger.
Nurses play a crucial role in educating new mothers about the importance of frequent and effective breastfeeding to establish a healthy milk supply, as this directly stimulates the prolactin reflex.
Understanding the difference between the production (prolactin) and ejection (oxytocin) reflexes helps nurses troubleshoot breastfeeding problems, such as a baby not getting enough milk despite a good supply (potential let-down issue).
What if? If a mother is exclusively pumping and not directly breastfeeding, the principle remains the same. The pump's stimulation mimics suckling, triggering the same prolactin reflex. The nurse's advice would be to pump frequently (every 2-3 hours), including at night, to maintain high prolactin levels.

How to Approach the Question

First, identify the core concept in the question: the 'prolactin reflex'.
Recall the basic physiology of lactation, which involves two key hormones: prolactin and oxytocin.
Differentiate the specific role of each hormone. A helpful mnemonic is that Prolactin is for milk 'Production'.
Evaluate the options based on this differentiation. 'Production of milk' directly matches the known function of prolactin.
Eliminate the other options: 'Ejection' is oxytocin's role, 'suppression' is the opposite effect, and 'storage' is a passive state, not an active reflex action.

Concept Tested & Keywords

Q5i8CIWrtMmLjSFuf1Fsuv

E6 Nutrition Kumud Khanna 2e p. 99-101

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

E6 Physiology Essentials Sembulingam 10e Part 2 p. 30-32