Strongest stimulus of lactation is?

Appeared in: PGIMER Chandigarh NO - 2015

Explanation

The single most potent stimulus for initiating and maintaining lactation is the infant's suckling at the nipple.
Suckling triggers nerve impulses to the hypothalamus, which in turn stimulates the pituitary gland.
This stimulation causes the anterior pituitary to release prolactin, the primary hormone responsible for milk synthesis (production).
Simultaneously, it causes the posterior pituitary to release oxytocin, which triggers the milk ejection reflex or "let-down," making milk available to the infant.

Option A: Postpartum Hemorrhage (PPH) does not stimulate lactation. Severe PPH can cause hypovolemic shock and pituitary ischemia (Sheehan's syndrome), which damages the pituitary gland and leads to lactation failure.
Option C: Coughing is a protective respiratory reflex to clear the airways and is physiologically unrelated to the neurohormonal pathways that control lactation.
Option D: Bromocriptine is a dopamine agonist. Dopamine is a natural inhibitor of prolactin. Therefore, bromocriptine acts to suppress prolactin secretion and is used medically to stop milk production.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Physiology of Lactation as background academic context rather than a clinical decision trigger.
A nurse's primary role in lactation support is to encourage early and frequent breastfeeding (8-12 times in 24 hours) to establish a robust milk supply.
Ensuring a proper latch is crucial. A poor latch is not only painful but also provides inadequate stimulation, leading to poor milk supply and nipple trauma.
Skin-to-skin contact immediately after birth and during feedings promotes the release of oxytocin, which aids the milk let-down reflex and enhances bonding.

How to Approach the Question

First, identify the core concept of the question, which is the primary trigger for lactation.
Recall the basic physiology of lactation, focusing on the key hormones involved: prolactin (for production) and oxytocin (for ejection/let-down).
Consider what action initiates the release of these hormones. The question asks for the 'strongest stimulus'.
Evaluate each option: 'Sucking' is a direct physical action by the infant on the nipple, known to trigger a neurohormonal reflex.
Analyze the other options. 'PPH' is a complication of childbirth. 'Coughing' is an unrelated reflex. 'Bromocriptine' is a medication.
Eliminate the incorrect options based on physiological knowledge. PPH can inhibit lactation. Coughing is irrelevant. Bromocriptine is a lactation suppressant. This leaves 'Sucking' as the only plausible and correct answer.

Concept Tested & Keywords

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E6 Obstetrics Williams p. 48-68

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

E6 Pharmacology Katzung 16e p. 1059-1061

Practise the full PGIMER Chandigarh NO - 2015

Attempt every question from this paper in a timed mock, then review the full solution for each one.