After the baby is born the hormone prolactin is stimulated from which endocrine gland?

AIIMS Raipur NO- 2019 (shift 3rd)

Applied Physiology

Easy

Appeared in: AIIMS Raipur NO- 2019 (shift 3rd)

Explanation

Prolactin is a hormone synthesized and secreted by specialized cells called lactotrophs, which are located in the anterior pituitary gland.
Its primary function after childbirth is to stimulate the production of milk (lactogenesis) within the alveolar cells of the mammary glands.
The release of prolactin is primarily triggered by the infant's suckling, which sends nerve signals to the hypothalamus, which in turn stimulates the anterior pituitary.
Following delivery, the sharp drop in progesterone and estrogen levels removes their inhibitory effect on the breast tissue, allowing prolactin to initiate milk synthesis.

Option B: The thyroid gland secretes thyroid hormones (T3 and T4) and calcitonin. These hormones are primarily responsible for regulating the body's metabolic rate and calcium homeostasis, not milk production.
Option C: The posterior pituitary does not produce prolactin. It stores and releases oxytocin and antidiuretic hormone (ADH). While oxytocin is crucial for lactation, its role is milk ejection (the 'let-down' reflex), not milk production.
Option D: Adrenaline (epinephrine) is a hormone produced by the adrenal medulla. It is part of the body's 'fight-or-flight' response to stress and has no primary role in stimulating milk production.

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 key role in educating new mothers that frequent and effective breastfeeding is essential for establishing and maintaining milk supply, as suckling is the primary stimulus for prolactin release.
Understanding the distinction between prolactin (production) and oxytocin (ejection) allows nurses to better troubleshoot breastfeeding challenges. For example, low milk supply may indicate a prolactin issue, whereas difficulty with milk let-down may relate to stress inhibiting oxytocin.
What if? If a postpartum patient is taking a dopamine agonist medication (e.g., bromocriptine for a pituitary tumor), the nurse should be aware that this can suppress prolactin secretion and lead to lactation failure, necessitating counseling on alternative feeding methods.

How to Approach the Question

First, identify the key hormone mentioned in the question: 'prolactin'.
Recall the primary physiological function of prolactin, which is the synthesis or production of milk (lactogenesis).
Access your knowledge of the endocrine system to identify which gland is responsible for producing prolactin.
Remember that the anterior pituitary gland produces several key hormones, including prolactin (PRL), growth hormone (GH), thyroid-stimulating hormone (TSH), and others.
Systematically eliminate the incorrect options by recalling their main functions: Thyroid (metabolism), Posterior Pituitary (stores/releases oxytocin for milk ejection), and Adrenaline (stress response from the adrenal gland).

Concept Tested & Keywords

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

E6 Obstetrics Williams p. 48-68